ARM: uniphier: de-couple SG macros into base address and offset

The SG_* macros represent the address of SoC-glue registers.
For a planned new SoC, its base address will be changed.

Turn the SG_* macros into the offset from the base address.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
diff --git a/arch/arm/mach-uniphier/dram_init.c b/arch/arm/mach-uniphier/dram_init.c
index fa4b3e3..eca340b 100644
--- a/arch/arm/mach-uniphier/dram_init.c
+++ b/arch/arm/mach-uniphier/dram_init.c
@@ -85,7 +85,7 @@
 		return -EINVAL;
 	}
 
-	val = readl(SG_MEMCONF);
+	val = readl(sg_base + SG_MEMCONF);
 
 	/* set up ch0 */
 	dram_map[0].base = CONFIG_SYS_SDRAM_BASE;