mac802154: monitor device support

Support for monitor device intended to capture all the network activity.
This interface could be used by networks sniffers and is already
supported by WireShark. That's a good test point to check that basic
MAC support works.

Signed-off-by: Alexander Smirnov <alex.bluesman.smirnov@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/linux/if_arp.h b/include/linux/if_arp.h
index 3718acf..26cb3c2 100644
--- a/include/linux/if_arp.h
+++ b/include/linux/if_arp.h
@@ -87,6 +87,7 @@
 #define ARPHRD_IEEE80211_PRISM 802	/* IEEE 802.11 + Prism2 header  */
 #define ARPHRD_IEEE80211_RADIOTAP 803	/* IEEE 802.11 + radiotap header */
 #define ARPHRD_IEEE802154	  804
+#define ARPHRD_IEEE802154_MONITOR 805	/* IEEE 802.15.4 network monitor */
 
 #define ARPHRD_PHONET	820		/* PhoNet media type		*/
 #define ARPHRD_PHONET_PIPE 821		/* PhoNet pipe header		*/