net/mlx5: DR, Expose steering table functionality

Tables are objects which are used for storing matchers, each table
belongs to a domain and defined by the domain type. When a packet
reaches the table it is being processed by each of its matchers until a
successful match. Tables can hold multiple matchers ordered by matcher
priority. Each table has a level.

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>