net/mlx5: HWS, added rules handling

Steering rule is a concept that includes match parameters for a flow,
and actions to perform on the flows that match these parameters.
This patch adds rules handling part of HW Steering.

Reviewed-by: Itamar Gozlan <igozlan@nvidia.com>
Signed-off-by: Yevgeny Kliteynik <kliteyn@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>