cfg80211: Prevent regulatory restore during STA disconnect in concurrent interfaces

cfg80211: Prevent regulatory restore during STA disconnect in concurrent interfaces

Currently when an AP and STA interfaces are active in the same or different
radios, regulatory settings are restored whenever the STA disconnects. This
restores all channel information including dfs states in all radios.
For example, if an AP interface is active in one radio and STA in another,
when radar is detected on the AP interface, the dfs state of the channel
will be changed to UNAVAILABLE. But when the STA interface disconnects,
this issues a regulatory disconnect hint which restores all regulatory
settings in all the radios attached and thereby losing the stored dfs
state on the other radio where the channel was marked as unavailable
earlier. Hence prevent such regulatory restore whenever another active
beaconing interface is present in the same or other radios.

Signed-off-by: Sriram R <srirrama@codeaurora.org>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>