{nl,cfg,mac}80211: let userspace set RANN interval

Allow userspace to set Root Announcement Interval for our mesh
interface. Also, RANN interval is now in proper units of TUs.

Signed-off-by: Javier Cardona <javier@cozybit.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/net/mac80211/mesh.c b/net/mac80211/mesh.c
index e120fef..1c4f53c3 100644
--- a/net/mac80211/mesh.c
+++ b/net/mac80211/mesh.c
@@ -537,7 +537,8 @@
 
 	mesh_path_tx_root_frame(sdata);
 	mod_timer(&ifmsh->mesh_path_root_timer,
-		  round_jiffies(jiffies + IEEE80211_MESH_RANN_INTERVAL));
+		  round_jiffies(jiffies +
+			  usecs_to_jiffies(ifmsh->mshcfg.dot11MeshHWMPRannInterval * 1024)));
 }
 
 #ifdef CONFIG_PM