MFC r347271:
Implement PCAM, MCAM access register commands in mlx5core.

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.

Linux commit:
c835ad64683bd3e2d1b31ed2cb1ff4366932edb1

Submitted by: slavash@
Sponsored by: Mellanox Technologies