allwinner: Reserve and map space for the SCP firmware

The SCP firmware is allocated the last 16KiB of SRAM A2. This includes
the SCPI shared memory area, which must be mapped as MT_DEVICE to
prevent problems with cache coherency between the AP CPUs and the SCP.
For simplicity, map the whole SCP region as MT_DEVICE.

Signed-off-by: Samuel Holland <samuel@sholland.org>
Change-Id: Ie39eb5ff281b8898a3c1d9748dc08755f528e2f8
diff --git a/plat/allwinner/common/sunxi_common.c b/plat/allwinner/common/sunxi_common.c
index 45e4154..0ca18ad 100644
--- a/plat/allwinner/common/sunxi_common.c
+++ b/plat/allwinner/common/sunxi_common.c
@@ -21,6 +21,8 @@
 static const mmap_region_t sunxi_mmap[PLATFORM_MMAP_REGIONS + 1] = {
 	MAP_REGION_FLAT(SUNXI_SRAM_BASE, SUNXI_SRAM_SIZE,
 			MT_RW_DATA | MT_SECURE),
+	MAP_REGION_FLAT(SUNXI_SCP_BASE, SUNXI_SCP_SIZE,
+			MT_DEVICE | MT_RW | MT_SECURE | MT_EXECUTE_NEVER),
 	MAP_REGION_FLAT(SUNXI_DEV_BASE, SUNXI_DEV_SIZE,
 			MT_DEVICE | MT_RW | MT_SECURE | MT_EXECUTE_NEVER),
 	MAP_REGION(SUNXI_DRAM_BASE, SUNXI_DRAM_VIRT_BASE, SUNXI_DRAM_SEC_SIZE,