MFC r347270:
Expose PCAM, MCAM registers infrastructure in mlx5core.

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).

Linux commit:
cfdcbceaeffc669b70d904d80a2df9c86c232566

Submitted by: slavash@
Sponsored by: Mellanox Technologies