In flow steering, if asked to, the hardware matches on the first ethertype
which is not vlan. It's possible to set a rule as follows, which is meant
to match on untagged packet, but will match on a vlan packet:
    tc filter add dev eth0 parent ffff: protocol ip flower ...

To avoid this for packets with single tag, we set vlan masks to tell
hardware to check the tags for every matched packet.

Fixes: 095b6cfd ('net/mlx5e: Add TC vlan match parsing')
Signed-off-by: Jianbo Liu <jianbol@mellanox.com>
Reviewed-by: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>