net/mlx5: E-Switch, Enable vport metadata matching if firmware supports it

As the ingress ACL rules save vhca id and vport number to packet's
metadata REG_C_0, and the metadata matching for the rules in both fast
path and slow path are all added, enable this feature if supported.

Signed-off-by: Jianbo Liu <jianbol@mellanox.com>
Reviewed-by: Roi Dayan <roid@mellanox.com>
Reviewed-by: Mark Bloch <markb@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>