net/mlx4_core: Add support for configuring RoCE v2 UDP port

In order to support RoCE v2, the hardware needs to be configured
to classify certain UDP packets as RoCE v2 packets and pass it
through its RoCE pipeline. This patch enables configuring this
UDP port.

Signed-off-by: Moni Shoua <monis@mellanox.com>
Signed-off-by: Matan Barak <matanb@mellanox.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>