net/mlx5: VLAN push on RX, pop on TX

net/mlx5: VLAN push on RX, pop on TX

Some older NIC hardware isn't capable of doing VLAN push on RX and pop
on TX.

A workaround has been added in software to support it, but it has a
performance penalty since it requires a hairpin + loopback.

There's no such limitation with the newer NICs, so no need to pay the
price of the w/a. With this change the software w/a is disabled for
certain HW versions and steering modes that support it.

Signed-off-by: Dima Chumak <dchumak@nvidia.com>
Reviewed-by: Oz Shlomo <ozsh@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>