mac80211: add beacon stats to debugfs

Beacon-timeout and number of beacon loss events.

Signed-off-by: Ben Greear <greearb@candelatech.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
diff --git a/net/mac80211/debugfs_sta.c b/net/mac80211/debugfs_sta.c
index 4f841fe..44e201d 100644
--- a/net/mac80211/debugfs_sta.c
+++ b/net/mac80211/debugfs_sta.c
@@ -54,6 +54,7 @@
 STA_FILE(dev, sdata->name, S);
 STA_FILE(last_signal, last_signal, D);
 STA_FILE(last_ack_signal, last_ack_signal, D);
+STA_FILE(beacon_loss_count, beacon_loss_count, D);
 
 static ssize_t sta_flags_read(struct file *file, char __user *userbuf,
 			      size_t count, loff_t *ppos)
@@ -434,6 +435,7 @@
 	DEBUGFS_ADD(agg_status);
 	DEBUGFS_ADD(dev);
 	DEBUGFS_ADD(last_signal);
+	DEBUGFS_ADD(beacon_loss_count);
 	DEBUGFS_ADD(ht_capa);
 	DEBUGFS_ADD(vht_capa);
 	DEBUGFS_ADD(last_ack_signal);