net/mlx5: Add structures and defines for MIRC register

Add needed structures, layouts and defines for MIRC (Management Image
Re-activation Control) register. This structure will be used for the FSM
reactivation flow in the downstream patches.

Signed-off-by: Eran Ben Elisha <eranbe@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>