net80211 changed a while back to support per-VAP config for things
rather than it being global. This is to support firmware NICs that
support per-VAP flags and configuration where the firmware will figure
out how to combine them.
However, it introduced a fun timing issue - those changes used to happen
to the shared ic state before newstate() was called, but now they're
also tasks and they can happen /after/.
This isn't a problem for ath(4), but it exposed some interesting
timing and config bugs here. Notably, I saw short slot NOT being
configured in 5GHz mode during some associations, so 5GHz stuff
would hang or behave poorly. Other times the follow-up auth has
the right config, so it didn't hang.
So for now, just flip this over to using the per-VAP flags which
are correct when newstate() is called. net80211 should also have
those flags synch'ed to the global ic state before newstate() runs
and that can come in a subsequent commit.
Whilst here also fix plcp to be consistently logged as a hex value.