cfg80211: Add nl80211 event for deletion of a station entry

Indicate an NL80211_CMD_DEL_STATION event when a station entry in
mac80211 is deleted to match with the NL80211_CMD_NEW_STATION event
that is used when the entry was added. This is needed, e.g., to allow
user space to remove a peer from RSN IBSS Authenticator state machine
to avoid re-authentication and re-keying delays when the peer is not
reachable anymore.

Signed-off-by: Jouni Malinen <jouni.malinen@atheros.com>
Reviewed-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/net/wireless/nl80211.h b/net/wireless/nl80211.h
index e3f7fa8..dcac5cd 100644
--- a/net/wireless/nl80211.h
+++ b/net/wireless/nl80211.h
@@ -79,6 +79,9 @@
 void nl80211_send_sta_event(struct cfg80211_registered_device *rdev,
 			    struct net_device *dev, const u8 *mac_addr,
 			    struct station_info *sinfo, gfp_t gfp);
+void nl80211_send_sta_del_event(struct cfg80211_registered_device *rdev,
+				struct net_device *dev, const u8 *mac_addr,
+				gfp_t gfp);
 
 int nl80211_send_mgmt(struct cfg80211_registered_device *rdev,
 		      struct net_device *netdev, u32 nlpid, int freq,