mac80211: fix radar_enabled propagation

mac80211: fix radar_enabled propagation

If chandef had non-HT width it was possible for
radar_enabled update to not be propagated properly
through drv_config(). This happened because
ieee80211_hw_conf_chan() would never see different
local->hw.conf.chandef and local->_oper_chandef.

This wasn't a problem with HT chandefs because
_oper_chandef width is reset to non-HT in
ieee80211_free_chanctx() making
ieee80211_hw_conf_chan() to kick in.

This problem led (at least) ath10k to not start
CAC if prior CAC was cancelled and both CACs were
requested for identical non-HT chandefs.

Signed-off-by: Michal Kazior <michal.kazior@tieto.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>