LinuxKPI: 802.11: synchronize LinuxKPI 802.11 sta from net80211 ni

Have a wrapper function dealing with the synchronization for all the
dfferent standards (HT and VHT currently).
In case HT or VHT is not supported make sure to turn the LinuxKPI
"supported" flag off for that. Previously if it was on once it would
never be turned off.
For HT and VHT properly compute the NSS and also set the max_amsdu_len
correctly.
Set the NSS directly in the function (which is called in proper order
for this) rather than passing the results back and do the setting in
the caller. The only thing we need to make sure upfront is that it
remains at least 1 (see f5a58c2da239). This all makes the caller and
code a tiny bit simpler and work better.

There is more synchronization to be done between the chanctx and the
deflink bandwidth, which needs to happen dynamically in case net80211
decides to change that under us but no native driver seems to properly
implement this (if at all).
HT20-only, HT40, and VHT80 are supposed to work for now at least.
VHT160 and VHT80P80 have further debug work to do as it does not yet
seem to be consistently set in all cases to sync from.

Sponsored by: The FreeBSD Foundation
MFC after: 3 days