net/mlx5: Add structures layout for new MCAM access reg groups

MCAM has 3 access_reg_groups (0-2). Defines data structures in order to
read and parse access_reg_groups #1 and #2.

Signed-off-by: Eran Ben Elisha <eranbe@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>