wifi: mac80211: make bss_param_ch_cnt available for the low level driver

wifi: mac80211: make bss_param_ch_cnt available for the low level driver

Drivers may need to track this. Make it available for them, and maintain
the value when beacons are received.
When link X receives a beacon, iterate the RNR elements and update all
the links with their respective data.
Track the link id that updated the data so that each link can know
whether the update came from its own beacon or from another link.
In case, the update came from the link's own beacon, always update the
updater link id.
The purpose is to let the low level driver know if a link is losing its
beacons. If link X is losing its beacons, it can still track the
bss_param_ch_cnt and know where the update came from.

Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
Signed-off-by: Miri Korenblit <miriam.rachel.korenblit@intel.com>
Link: https://patch.msgid.link/20241007144851.e2d8d1a722ad.I04b883daba2cd48e5730659eb62ca1614c899cbb@changeid
Signed-off-by: Johannes Berg <johannes.berg@intel.com>