bridge: mdb: add support for offloaded mdb entries

Add new bitmask member 'flags' to br_mdb_entry structure. Adding
MDB_FLAGS_OFFLOAD bit which indicates MDB entries is offloaded to hardware.

Signed-off-by: Elad Raz <eladr@mellanox.com>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/uapi/linux/if_bridge.h

@@ -183,6 +183,8 @@ struct br_mdb_entry {
 #define MDB_TEMPORARY 0
 #define MDB_PERMANENT 1
 	__u8 state;
+#define MDB_FLAGS_OFFLOAD	(1 << 0)
+	__u8 flags;
 	__u16 vid;
 	struct {
 		union {