{nl,cfg,mac}80211: implement dot11MeshHWMPperrMinInterval

As per 802.11mb 13.9.11.3

Signed-off-by: Thomas Pedersen <thomas@cozybit.com>
Signed-off-by: Javier Cardona <javier@cozybit.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h
index 7a757a9..a785d61 100644
--- a/net/mac80211/ieee80211_i.h
+++ b/net/mac80211/ieee80211_i.h
@@ -514,7 +514,9 @@
 	atomic_t mpaths;
 	/* Timestamp of last SN update */
 	unsigned long last_sn_update;
-	/* Timestamp of last SN sent */
+	/* Time when it's ok to send next PERR */
+	unsigned long next_perr;
+	/* Timestamp of last PREQ sent */
 	unsigned long last_preq;
 	struct mesh_rmc *rmc;
 	spinlock_t mesh_preq_queue_lock;