cfg80211: add nl80211 beacon-only statistics

Add these two values:
 * BEACON_RX: number of beacons received from this peer
 * BEACON_SIGNAL_AVG: signal strength average for beacons only

These can then be used for Android Lollipop's statistics request.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
diff --git a/include/net/cfg80211.h b/include/net/cfg80211.h
index 91c1336..ef26ce1 100644
--- a/include/net/cfg80211.h
+++ b/include/net/cfg80211.h
@@ -987,6 +987,9 @@
  * @nonpeer_pm: non-peer mesh STA power save mode
  * @expected_throughput: expected throughput in kbps (including 802.11 headers)
  *	towards this station.
+ * @rx_beacon: number of beacons received from this peer
+ * @rx_beacon_signal_avg: signal strength average (in dBm) for beacons received
+ *	from this peer
  */
 struct station_info {
 	u32 filled;
@@ -1026,6 +1029,9 @@
 	enum nl80211_mesh_power_mode nonpeer_pm;
 
 	u32 expected_throughput;
+
+	u64 rx_beacon;
+	u8 rx_beacon_signal_avg;
 };
 
 /**