lan78xx ethernet done for Pi3B+

[LdB-ECM]

I ported the lan78xx driver onto xinu but wonder how you want me to push back the directory structure

I am using
ethernet --- Holds files common to both drivers
ethernet\smsc9512 ---- smsc9512 files for orginal ethernet
ethernet\lan78xx ---- lan78xx files for Pi3B+

This doesn't really match your existing flat structure

There is one issue with the port the testsuite fails on the driver because it looks like it injects some sort of packet capture manually. The RX overhead is different between the two and I guess it crashes.

I can bring the netup and do everything via the ethernet so I am pretty sure there isn't a issue just something about the testsuite.