plat/marvell/armada/common/mss: use MSS SRAM in secure mode

The CP MSS IRAM is only accessible by CM3 CPU and MSS DMA.
In secure boot mode the MSS DMA is unable to directly load
the MSS FW image from DRAM to IRAM.
This patch adds support for using the MSS SRAM as intermediate
storage. The MSS FW image is loaded by application CPU into the
MSS SRAM first, then transferred to MSS IRAM by MSS DMA.
Such change allows the CP MSS image load in secure mode.

Change-Id: Iee7a51d157743a0bdf8acb668ee3d599f760a712
Signed-off-by: Konstantin Porotchkin <kostap@marvell.com>
Reviewed-by: Stefan Chulski <stefanc@marvell.com>
Reviewed-by: Grzegorz Jaszczyk <jaszczyk@marvell.com>
diff --git a/plat/marvell/armada/common/mss/mss_scp_bl2_format.h b/plat/marvell/armada/common/mss/mss_scp_bl2_format.h
index 74dddc6..90913b0 100644
--- a/plat/marvell/armada/common/mss/mss_scp_bl2_format.h
+++ b/plat/marvell/armada/common/mss/mss_scp_bl2_format.h
@@ -13,6 +13,7 @@
 #define HEADER_VERSION	0x1
 
 #define MSS_IDRAM_SIZE	0x10000 /* 64KB */
+#define MSS_SRAM_SIZE	0x8000 /* 32KB */
 
 /* Types definitions */
 typedef struct file_header {