plat-hikey: make DRAM0_SIZE and DRAM0_SIZE_NSEC configurable

DRAM0_SIZE is now defined as CFG_TZDRAM_START, allowing
for dynamic configuration.

DRAM0_SIZE_NSEC is modified to calculate the size relative
to DRAM0_BASE.

Signed-off-by: Wen Bin <a1231512a@163.com>

core/arch/arm/plat-hikey/platform_config.h

@@ -105,7 +105,8 @@
  */
 
 #define DRAM0_BASE		0x00000000
-#define DRAM0_SIZE		0x3F000000
+/* DRAM0 exists below TZDRAM */
+#define DRAM0_SIZE		(CFG_TZDRAM_START - DRAM0_BASE)
 #define DRAM0_SIZE_NSEC		0x3E000000
 #define DRAM1_BASE		CFG_DRAM1_BASE
 
@@ -130,7 +131,7 @@
 #if (CFG_DRAM_SIZE_GB == 3)
 #define DRAM1_SIZE_NSEC		0x80000000
 #elif (CFG_DRAM_SIZE_GB == 4)
-#define DRAM1_SIZE_NSEC		0xA0000000
+#define DRAM1_SIZE_NSEC		(0xE0000000 - DRAM1_BASE)
 #define DRAM2_BASE		0x200000000
 #define DRAM2_SIZE_NSEC		0x20000000
 #elif (CFG_DRAM_SIZE_GB == 6)