batman-adv: Distributed ARP Table - add a new debug log level

A new log level has been added to concentrate messages regarding DAT: ARP
snooping, requests, response and DHT related messages.
The new log level is named BATADV_DBG_DAT

Signed-off-by: Antonio Quartulli <ordex@autistici.org>
diff --git a/Documentation/networking/batman-adv.txt b/Documentation/networking/batman-adv.txt
index a173d2a..c1d8204 100644
--- a/Documentation/networking/batman-adv.txt
+++ b/Documentation/networking/batman-adv.txt
@@ -203,7 +203,8 @@
 2 - Enable messages related to route added / changed / deleted
 4 - Enable messages related to translation table operations
 8 - Enable messages related to bridge loop avoidance
-15 - enable all messages
+16 - Enable messaged related to DAT, ARP snooping and parsing
+31 - Enable all messages
 
 The debug output can be changed at runtime  using  the  file
 /sys/class/net/bat0/mesh/log_level. e.g.