wifi: mac80211: don't connect to an AP while it's in a CSA process

Connection to an AP that is running a CSA flow may end up with a
failure as the AP might change its channel during the connection
flow while we do not track the channel change yet.
Avoid that by rejecting a connection to such an AP.

Signed-off-by: Ayala Beker <ayala.beker@intel.com>
Signed-off-by: Gregory Greenman <gregory.greenman@intel.com>
Link: https://lore.kernel.org/r/20230920211508.e5001a762a4a.I9745c695f3403b259ad000ce94110588a836c04a@changeid
Signed-off-by: Johannes Berg <johannes.berg@intel.com>