net: bridge: multicast: add vlan querier and query support

Add basic vlan context querier support, if the contexts passed to
multicast_alloc_query are vlan then the query will be tagged. Also
handle querier start/stop of vlan contexts.

Signed-off-by: Nikolay Aleksandrov <nikolay@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>