wifi: mac80211: validate assoc response channel config

Due to the earlier restructuring we now mostly ignore
the channel configuration in the association response,
apart from the HT/VHT checks we had.

Don't do that, but parse it and update, also dropping the
association if the AP changed its mode in the response.

Link: https://msgid.link/20240129194108.b3efa5eae60c.I1b70c9fd56781b22cdfdca55d34d69f7d0733e31@changeid


Signed-off-by: Johannes Berg <johannes.berg@intel.com>