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>
diff --git a/plat/marvell/armada/a8k/a70x0_amc/board/marvell_plat_config.c b/plat/marvell/armada/a8k/a70x0_amc/board/marvell_plat_config.c
index 7fc33f1..3b68e91 100644
--- a/plat/marvell/armada/a8k/a70x0_amc/board/marvell_plat_config.c
+++ b/plat/marvell/armada/a8k/a70x0_amc/board/marvell_plat_config.c
@@ -94,7 +94,10 @@
 	{0x00000000f2000000,	0x4000000,	IO_0_TID}, /* IO window */
 #else
 #if LLC_SRAM
-	{PLAT_MARVELL_LLC_SRAM_BASE, PLAT_MARVELL_LLC_SRAM_SIZE, SRAM_TID},
+	/* This entry is prepared for OP-TEE OS that enables the LLC SRAM
+	 * and changes the window target to SRAM_TID.
+	 */
+	{PLAT_MARVELL_LLC_SRAM_BASE, PLAT_MARVELL_LLC_SRAM_SIZE, DRAM_0_TID},
 #endif
 	{0x00000000f2000000,	0xe000000,	IO_0_TID},
 	{0x00000000c0000000,    0x30000000,	IO_0_TID}, /* IO window */