For DWDS VAPs on ath(4) we need to ensure that the STA vap and hostap VAP
have different MAC addresses. If the STA code path doesn't utilise the
address assign / reclaim path then it doesn't update the bitmap with which
address was allocated.
This should fix a bunch of corner issues I've been seeing with DWDS STA + AP
VAPs that I was working around with manual MAC address assignment.