net/mlx4: Strengthen VLAN tags/priorities enforcement in VST mode

Make sure that the following steps are taken:

- drop packets sent by the VF with vlan tag
- block packets with vlan tag which are steered to the VF
- drop/block tagged packets when the policy is priority-tagged
- make sure VLAN stripping for received packets is set
- make sure force UP bit for the VF QP is set

Use enum values for all the above instead of numerical bit offsets.

Signed-off-by: Rony Efraim <ronye@mellanox.com>
Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>