net/mlx5: Lag, enable hash mode by default for all NICs

The firmware supports adding a steering rule to catch egress traffic
of the QPs/TISs which are set port affinity explicitly in hash mode.
Enable that mode for NICS with 2 ports as well.

Signed-off-by: Liu, Changcheng <jerrliu@nvidia.com>
Reviewed-by: Mark Bloch <mbloch@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>