bridge: Implement vlan ingress/egress policy with PVID.

At ingress, any untagged traffic is assigned to the PVID.
Any tagged traffic is filtered according to membership bitmap.

At egress, if the vlan matches the PVID, the frame is sent
untagged.  Otherwise the frame is sent tagged.

Signed-off-by: Vlad Yasevich <vyasevic@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>