switchdev: add bridge vlan_filtering attribute

Adding vlan_filtering attribute to allow hardware vendor to support
vlan-aware bridges. Vlan_filtering is a per-bridge attribute.

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>