uniphier: shrink UNIPHIER_ROM_REGION_SIZE

Currently, the ROM region is needlessly too large.

The on-chip SRAM region of the next SoC will start from 0x04000000,
and this will cause the region overlap.

Mapping 0x04000000 for the ROM is enough.

Change-Id: I85ce0bb1120ebff2e3bc7fd13dc0fd15dfff5ff6
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>

plat/socionext/uniphier/uniphier_io_storage.c

@@ -21,7 +21,7 @@
 #include "uniphier.h"
 
 #define UNIPHIER_ROM_REGION_BASE	0x00000000ULL
-#define UNIPHIER_ROM_REGION_SIZE	0x10000000ULL
+#define UNIPHIER_ROM_REGION_SIZE	0x04000000ULL
 
 #define UNIPHIER_OCM_REGION_SIZE	0x00040000ULL