MFC r347286:
Add mlxfw callbacks in mlx5core.

Add mlx5 implementation for the ones defined by the mlxfw
shared module to be used while flashing the device firmware.

The callbacks do their job through the MCQI, MCC and MCDA registers.

Linux commit:
62bd22cf326dc4ac5be673c11cef4602dc1f5e47

Submitted by: slavash@
Sponsored by: Mellanox Technologies