mac80211: set mesh formation field properly

Cap max peerings at 63 in accordance with IEEE-2012 8.4.2.100.7.
Triggers a beacon regeneration every time the number of peerings changes.
Previously this would only happen if the "accepting peerings" bit changed.

Signed-off-by: Jacob Minshall <jacob@cozybit.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
diff --git a/include/linux/ieee80211.h b/include/linux/ieee80211.h
index d826e5a..b0dc87a 100644
--- a/include/linux/ieee80211.h
+++ b/include/linux/ieee80211.h
@@ -146,6 +146,7 @@
 #define IEEE80211_MAX_RTS_THRESHOLD	2353
 #define IEEE80211_MAX_AID		2007
 #define IEEE80211_MAX_TIM_LEN		251
+#define IEEE80211_MAX_MESH_PEERINGS	63
 /* Maximum size for the MA-UNITDATA primitive, 802.11 standard section
    6.2.1.1.2.