arm64: mvebu: Fix A8K memory mapping and add documentation

arm64: mvebu: Fix A8K memory mapping and add documentation

Fix the MMU mapping for A8K device family:
 - Separate A7K and A8K memory mappings
 - Fix memory regions by including IO mapping for all
   3 PCIe interfaces existing on each connected CP110 controller
Add A8K memory mapping documentation with all regions
configured by Marvell ATF.

Change-Id: I9c930569b1853900f5fba2d5db319b092cc7a2a6
Signed-off-by: Konstantin Porotchkin <[email protected]>
Signed-off-by: Stefan Roese <[email protected]>
Cc: Stefan Roese <[email protected]>
Cc: Nadav Haklai <[email protected]>
Cc: Neta Zur Hershkovits <[email protected]>
Cc: Omri Itach <[email protected]>
Cc: Igal Liberman <[email protected]>
Cc: Haim Boot <[email protected]>
Cc: Hanna Hawa <[email protected]>