udev: Handle AMBA bus the same way as generic platform bus

On various ARM systems, it is possible to find devices on AMBA bus.
This is defined in Linux kernel drivers/amba/bus.c as separate bus
type. Udev currently does not recognize this when building ID_PATH
which leads to ID_PATH containing the suffix from next recognized
parent device. On ST STM32MP15xx with SDIO WiFi, the ID_PATH looks
like 'platform-soc', which is not unique and basically useless. On
NXP i.MX8M Plus with SDIO WiFi, ID_PATH is 'platform-30b40000.mmc'
which is far more useful.

Add the 'amba' subsystem handling the same way 'platform' subsystem
is handled to get ID_PATH 'platform-soc-amba-48004000.sdmmc' on the
former, which is far more useful compared to 'platform-soc'.

---

```
$ udevadm info --attribute-walk --path=/devices/platform/soc/48004000.mmc/mmc_host/mmc1/mmc1:0001/mmc1:0001:1/net/wlan0

Udevadm info starts with the device specified by the devpath and then
walks up the chain of parent devices. It prints for every device
found, all possible attributes in the udev rules key format.
A rule to match, can be composed by the attributes of the device
and the attributes from one single parent device.

  looking at device '/devices/platform/soc/48004000.mmc/mmc_host/mmc1/mmc1:0001/mmc1:0001:1/net/wlan0':
    KERNEL=="wlan0"
    SUBSYSTEM=="net"
    DRIVER==""
    ATTR{addr_assign_type}=="0"
    ATTR{addr_len}=="6"
    ATTR{address}=="10:98:c3:5f:4b:80"
    ATTR{broadcast}=="ff:ff:ff:ff:ff:ff"
    ATTR{carrier_changes}=="1"
    ATTR{carrier_down_count}=="1"
    ATTR{carrier_up_count}=="0"
    ATTR{dev_id}=="0x0"
    ATTR{dev_port}=="0"
    ATTR{flags}=="0x1002"
    ATTR{gro_flush_timeout}=="0"
    ATTR{ifalias}==""
    ATTR{ifindex}=="3"
    ATTR{iflink}=="3"
    ATTR{link_mode}=="0"
    ATTR{mtu}=="1500"
    ATTR{napi_defer_hard_irqs}=="0"
    ATTR{netdev_group}=="0"
    ATTR{operstate}=="down"
    ATTR{power/control}=="auto"
    ATTR{power/runtime_active_time}=="0"
    ATTR{power/runtime_status}=="unsupported"
    ATTR{power/runtime_suspended_time}=="0"
    ATTR{proto_down}=="0"
    ATTR{queues/rx-0/rps_cpus}=="0"
    ATTR{queues/rx-0/rps_flow_cnt}=="0"
    ATTR{queues/tx-0/byte_queue_limits/hold_time}=="1000"
    ATTR{queues/tx-0/byte_queue_limits/inflight}=="0"
    ATTR{queues/tx-0/byte_queue_limits/limit}=="0"
    ATTR{queues/tx-0/byte_queue_limits/limit_max}=="1879048192"
    ATTR{queues/tx-0/byte_queue_limits/limit_min}=="0"
    ATTR{queues/tx-0/tx_maxrate}=="0"
    ATTR{queues/tx-0/tx_timeout}=="0"
    ATTR{queues/tx-0/xps_rxqs}=="0"
    ATTR{statistics/collisions}=="0"
    ATTR{statistics/multicast}=="0"
    ATTR{statistics/rx_bytes}=="0"
    ATTR{statistics/rx_compressed}=="0"
    ATTR{statistics/rx_crc_errors}=="0"
    ATTR{statistics/rx_dropped}=="0"
    ATTR{statistics/rx_errors}=="0"
    ATTR{statistics/rx_fifo_errors}=="0"
    ATTR{statistics/rx_frame_errors}=="0"
    ATTR{statistics/rx_length_errors}=="0"
    ATTR{statistics/rx_missed_errors}=="0"
    ATTR{statistics/rx_nohandler}=="0"
    ATTR{statistics/rx_over_errors}=="0"
    ATTR{statistics/rx_packets}=="0"
    ATTR{statistics/tx_aborted_errors}=="0"
    ATTR{statistics/tx_bytes}=="0"
    ATTR{statistics/tx_carrier_errors}=="0"
    ATTR{statistics/tx_compressed}=="0"
    ATTR{statistics/tx_dropped}=="0"
    ATTR{statistics/tx_errors}=="0"
    ATTR{statistics/tx_fifo_errors}=="0"
    ATTR{statistics/tx_heartbeat_errors}=="0"
    ATTR{statistics/tx_packets}=="0"
    ATTR{statistics/tx_window_errors}=="0"
    ATTR{threaded}=="0"
    ATTR{tx_queue_len}=="1000"
    ATTR{type}=="1"

  looking at parent device '/devices/platform/soc/48004000.mmc/mmc_host/mmc1/mmc1:0001/mmc1:0001:1':
    KERNELS=="mmc1:0001:1"
    SUBSYSTEMS=="sdio"
    DRIVERS=="brcmfmac"
    ATTRS{class}=="0x00"
    ATTRS{coredump}=="(write-only)"
    ATTRS{device}=="0xa9bf"
    ATTRS{power/control}=="auto"
    ATTRS{power/runtime_active_time}=="0"
    ATTRS{power/runtime_status}=="unsupported"
    ATTRS{power/runtime_suspended_time}=="0"
    ATTRS{revision}=="0.0"
    ATTRS{vendor}=="0x02d0"

  looking at parent device '/devices/platform/soc/48004000.mmc/mmc_host/mmc1/mmc1:0001':
    KERNELS=="mmc1:0001"
    SUBSYSTEMS=="mmc"
    DRIVERS==""
    ATTRS{device}=="0xa9bf"
    ATTRS{ocr}=="0x00200000"
    ATTRS{power/control}=="auto"
    ATTRS{power/runtime_active_time}=="0"
    ATTRS{power/runtime_status}=="unsupported"
    ATTRS{power/runtime_suspended_time}=="0"
    ATTRS{rca}=="0x0001"
    ATTRS{revision}=="0.0"
    ATTRS{type}=="SDIO"
    ATTRS{vendor}=="0x02d0"

  looking at parent device '/devices/platform/soc/48004000.mmc/mmc_host/mmc1':
    KERNELS=="mmc1"
    SUBSYSTEMS=="mmc_host"
    DRIVERS==""
    ATTRS{power/control}=="auto"
    ATTRS{power/runtime_active_time}=="0"
    ATTRS{power/runtime_status}=="unsupported"
    ATTRS{power/runtime_suspended_time}=="0"

  looking at parent device '/devices/platform/soc/48004000.mmc':
    KERNELS=="48004000.mmc"
    SUBSYSTEMS=="amba" <------------------------------------------------------- AMBA is here
    DRIVERS=="mmci-pl18x"
    ATTRS{driver_override}=="(null)"
    ATTRS{id}=="00253180"
    ATTRS{power/autosuspend_delay_ms}=="50"
    ATTRS{power/control}=="on"
    ATTRS{power/runtime_active_time}=="666709"
    ATTRS{power/runtime_status}=="active"
    ATTRS{power/runtime_suspended_time}=="0"

  looking at parent device '/devices/platform/soc':
    KERNELS=="soc"
    SUBSYSTEMS=="platform"
    DRIVERS=="simple-pm-bus"
    ATTRS{driver_override}=="(null)"
    ATTRS{power/control}=="auto"
    ATTRS{power/runtime_active_time}=="0"
    ATTRS{power/runtime_status}=="unsupported"
    ATTRS{power/runtime_suspended_time}=="0"

  looking at parent device '/devices/platform':
    KERNELS=="platform"
    SUBSYSTEMS==""
    DRIVERS==""
    ATTRS{power/control}=="auto"
    ATTRS{power/runtime_active_time}=="0"
    ATTRS{power/runtime_status}=="unsupported"
    ATTRS{power/runtime_suspended_time}=="0"
```

src/udev/udev-builtin-path_id.c

@@ -631,6 +631,13 @@ static int builtin_path_id(sd_device *dev, sd_netlink **rtnl, int argc, char *ar
  parent = skip_subsystem(parent, "platform");
  supported_transport = true;
  supported_parent = true;
+ } else if (streq(subsys, "amba")) {
+ path_prepend(&path, "amba-%s", sysname);
+ if (compat_path)
+ path_prepend(&compat_path, "amba-%s", sysname);
+ parent = skip_subsystem(parent, "amba");
+ supported_transport = true;
+ supported_parent = true;
  } else if (streq(subsys, "acpi")) {
  path_prepend(&path, "acpi-%s", sysname);
  if (compat_path)