fix bss transition firmware crash

fixes: ath11k: fix peer addition/deletion error on sta band migration: d673cb6fe6c03b2be157cc6c5db40481828d282d

the fix for sta band migration raises a new bug which causes the wifi
firmware to crash if you switch between 2 bssid's on the same band. this is
usually caused since the firmware observes 2 stations with the same
bss

Signed-off-by: Sebastian Gottschall <[email protected]>