IB/mlx5: Add create_cq extended command

In order to create a CQ that supports timestamp, mlx5 needs to
support the extended create CQ command with the timestamp flag.

Signed-off-by: Matan Barak <matanb@mellanox.com>
Reviewed-by: Eli Cohen <eli@mellanox.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>