net/mlx5: DR, Expose steering matcher functionality

Matcher defines which packets fields are matched when a packet arrives.
Matcher is a part of a table and can contain one or more rules. Where
rule defines specific values of the matcher's mask definition.

Signed-off-by: Alex Vesker <valex@mellanox.com>
Reviewed-by: Erez Shitrit <erezsh@mellanox.com>
Reviewed-by: Mark Bloch <markb@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>