net/mlx5: Expose PCAM, MCAM registers infrastructure

PCAM: Ports capabilities mask register.
MCAM: Management capabilities mask register.

PCAM and MCAM registers will provide information regarding firmware
support for different features, in order to avoid cases where new driver
combined with old firmware results in syndromes (for ex. PCIe counters
before this patchset).

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