cfg80211: introduce cfg80211_stop_ap

This functionality will be reused when interface
is going down. Avoids code duplication. Also adds
missing wdev locking.

Signed-off-by: Michal Kazior <michal.kazior@tieto.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
diff --git a/net/wireless/core.h b/net/wireless/core.h
index 609a579..fef476d2 100644
--- a/net/wireless/core.h
+++ b/net/wireless/core.h
@@ -289,6 +289,10 @@
 			   struct wireless_dev *wdev, int freq,
 			   enum nl80211_channel_type channel_type);
 
+/* AP */
+int cfg80211_stop_ap(struct cfg80211_registered_device *rdev,
+		     struct net_device *dev);
+
 /* MLME */
 int __cfg80211_mlme_auth(struct cfg80211_registered_device *rdev,
 			 struct net_device *dev,