nl80211/mac80211: define and allow configuring mesh element TTL

The TTL in path selection information elements is different from
the mesh ttl used in mesh data frames.  Version 7.03 of the 11s
draft calls this ttl 'Element TTL'.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/include/net/cfg80211.h b/include/net/cfg80211.h
index 6b2af7a..93a4b20 100644
--- a/include/net/cfg80211.h
+++ b/include/net/cfg80211.h
@@ -624,6 +624,8 @@
 	u16 dot11MeshMaxPeerLinks;
 	u8  dot11MeshMaxRetries;
 	u8  dot11MeshTTL;
+	/* ttl used in path selection information elements */
+	u8  element_ttl;
 	bool auto_open_plinks;
 	/* HWMP parameters */
 	u8  dot11MeshHWMPmaxPREQretries;