IB/mlx5: Add support for active_width and active_speed in RoCE

Add missing calculation and translation of active_width and
active_speed for RoCE.

Fixes: 3f89a643 ('IB/mlx5: Extend query_device/port to ...')
Signed-off-by: Noa Osherovich <noaos@mellanox.com>
Signed-off-by: Eran Ben Elisha <eranbe@mellanox.com>
Signed-off-by: Leon Romanovsky <leon@kernel.org>
Signed-off-by: Doug Ledford <dledford@redhat.com>