net/mlx5: Implement PCAM, MCAM access register commands

Introduced registers will expose capabilities of new registers and
features related to port/management.
Driver will query MCAM and PCAM in order to avoid failing on old
firmwares with lack of support.

Signed-off-by: Gal Pressman <galp@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>