IB/mlx4: Expose RSS capabilities

As a final step to support RSS feature, expose the RSS capabilities in
query device verb.

It includes:
- Max rwq indirection tables.
- Max rwq indirection table size.
- Supported qp types.

Signed-off-by: Guy Levi <guyle@mellanox.com>
Reviewed-by: Yishai Hadas <yishaih@mellanox.com>
Signed-off-by: Leon Romanovsky <leon@kernel.org>
Signed-off-by: Doug Ledford <dledford@redhat.com>