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/linux/nl80211.h b/include/linux/nl80211.h
index 5cfa579..9e54145 100644
--- a/include/linux/nl80211.h
+++ b/include/linux/nl80211.h
@@ -1547,6 +1547,9 @@
  * @NL80211_MESHCONF_TTL: specifies the value of TTL field set at a source mesh
  * point.
  *
+ * @NL80211_MESHCONF_ELEMENT_TTL: specifies the value of TTL field set at a
+ * source mesh point for path selection elements.
+ *
  * @NL80211_MESHCONF_AUTO_OPEN_PLINKS: whether we should automatically
  * open peer links when we detect compatible mesh peers.
  *
@@ -1593,6 +1596,7 @@
 	NL80211_MESHCONF_HWMP_PREQ_MIN_INTERVAL,
 	NL80211_MESHCONF_HWMP_NET_DIAM_TRVS_TIME,
 	NL80211_MESHCONF_HWMP_ROOTMODE,
+	NL80211_MESHCONF_ELEMENT_TTL,
 
 	/* keep last */
 	__NL80211_MESHCONF_ATTR_AFTER_LAST,