wifi: mac80211: Support multi link in ieee80211_recalc_min_chandef()

Recalculate min channel context for the given or all interface
links, depending on the caller. For a station state change, we
need to recalculate all of them since we don't know which link
(or multiple) it might be on.

Signed-off-by: Andrei Otcheretianski <andrei.otcheretianski@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>