bridge: netlink: add group_addr support

Add IFLA_BR_GROUP_ADDR attribute to allow setting and retrieving the
group_addr via netlink.

Signed-off-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/uapi/linux/if_link.h b/include/uapi/linux/if_link.h
index a1e3328..eaeaac1 100644
--- a/include/uapi/linux/if_link.h
+++ b/include/uapi/linux/if_link.h
@@ -243,6 +243,7 @@
 	IFLA_BR_TCN_TIMER,
 	IFLA_BR_TOPOLOGY_CHANGE_TIMER,
 	IFLA_BR_GC_TIMER,
+	IFLA_BR_GROUP_ADDR,
 	__IFLA_BR_MAX,
 };