net/mlx5: E-Switch, Verify support QoS element type

Check if firmware supports the requested element type before
attempting to create the element type.
In addition, explicitly specify the request element type and tsar type.

Signed-off-by: Eli Cohen <eli@mellanox.com>
Reviewed-by: Paul Blakey <paulb@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>