refactor(ast2700): update memory layout

Update the memory layout for both BL31 and BL32 FW based on
the 1GB DRAM space of the AST2700 EVB.

Minor:
 - Use SZ_xx macro to define size for better readability

Signed-off-by: Chia-Wei Wang <chiawei_wang@aspeedtech.com>
Change-Id: I6d8285bd675321f615bb67cdd27bb4b6cb4c8b16
diff --git a/plat/aspeed/ast2700/include/platform_def.h b/plat/aspeed/ast2700/include/platform_def.h
index 3f2468f..8be26c3 100644
--- a/plat/aspeed/ast2700/include/platform_def.h
+++ b/plat/aspeed/ast2700/include/platform_def.h
@@ -41,13 +41,13 @@
 #define MAX_MMAP_REGIONS		U(32)
 
 /* BL31 region */
-#define BL31_BASE			ULL(0x400000000)
-#define BL31_SIZE			ULL(0x400000)
+#define BL31_BASE			ULL(0x430000000)
+#define BL31_SIZE			SZ_512K
 #define BL31_LIMIT			(BL31_BASE + BL31_SIZE)
 
 /* BL32 region */
 #define BL32_BASE			BL31_LIMIT
-#define BL32_SIZE			ULL(0x400000)
+#define BL32_SIZE			SZ_16M
 #define BL32_LIMIT			(BL32_BASE + BL32_SIZE)
 
 /* console */