plat: marvell: armada: a8k: change CCU LLC SRAM mapping

The LLC SRAM will be enabled in OP-TEE OS for usage as secure storage.
The CCU have to prepare SRAM window, but point to the DRAM-0 target
until the SRAM is actually enabled.
This patch changes CCU SRAM window target to DRAM-0
Remove dependence between LLC_SRAM and LLC_ENABLE and update the
build documentation.
The SRAМ base moved to follow the OP-TEE SHMEM area (0x05400000)

Change-Id: I85c2434a3d515ec37da5ae8eb729e3280f91c456
Signed-off-by: Konstantin Porotchkin <kostap@marvell.com>
7 files changed