wireless: move mesh config length constant

This is a constant from the 802.11 specification.

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Cc: Javier Cardona <javier@cozybit.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/include/linux/ieee80211.h b/include/linux/ieee80211.h
index aad9919..9dc288b 100644
--- a/include/linux/ieee80211.h
+++ b/include/linux/ieee80211.h
@@ -97,7 +97,10 @@
 #define IEEE80211_MAX_FRAME_LEN		2352
 
 #define IEEE80211_MAX_SSID_LEN		32
+
 #define IEEE80211_MAX_MESH_ID_LEN	32
+#define IEEE80211_MESH_CONFIG_LEN	19
+
 #define IEEE80211_QOS_CTL_LEN		2
 #define IEEE80211_QOS_CTL_TID_MASK	0x000F
 #define IEEE80211_QOS_CTL_TAG1D_MASK	0x0007