This adds support for PF control over the VF vlan configuration.
I.e., `ip link ... vf <x> vlan <vid>' should now be supported.

 1. <vid> != 0 => VF receives [unknowingly] only traffic tagged by
    <vid> and tags all outgoing traffic sent by VF with <vid>.
 2. <vid> == 0 ==> Remove the pvid configuration, reverting to previous.
Signed-off-by: Yuval Mintz <Yuval.Mintz@qlogic.com>
Signed-off-by: David S. Miller <davem@davemloft.net>