This patch exposes PRM layout for handling MPEGC (Management PCIe
General Configuration).

This will be used in the downstream patch for configuring MPEGC via the
driver.
Signed-off-by: Eran Ben Elisha <eranbe@mellanox.com>
Reviewed-by: Moshe Shemesh <moshe@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>