Phonet: provide MAC header operations

Signed-off-by: RĂ©mi Denis-Courmont <remi.denis-courmont@nokia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/linux/if_phonet.h b/include/linux/if_phonet.h
index 22df25f..7e98921 100644
--- a/include/linux/if_phonet.h
+++ b/include/linux/if_phonet.h
@@ -12,3 +12,7 @@
 /* 6 bytes header + 65535 bytes payload */
 #define PHONET_MAX_MTU		65541
 #define PHONET_DEV_MTU		PHONET_MAX_MTU
+
+#ifdef __KERNEL__
+extern struct header_ops phonet_header_ops;
+#endif