mpc83xx: Get rid of CONFIG_SYS_DDR_BASE

CONFIG_SYS_DDR_BASE is specific to mpc83xx an is always set to the same
value as CONFIG_SYS_SDRAM_BASE. Just use CONFIG_SYS_SDRAM_BASE instead.

Signed-off-by: Mario Six <mario.six@gdsys.cc>
diff --git a/include/configs/MPC8315ERDB.h b/include/configs/MPC8315ERDB.h
index b49022b..c5a229d 100644
--- a/include/configs/MPC8315ERDB.h
+++ b/include/configs/MPC8315ERDB.h
@@ -34,9 +34,8 @@
 /*
  * DDR Setup
  */
-#define CONFIG_SYS_DDR_BASE		0x00000000 /* DDR is system memory */
-#define CONFIG_SYS_SDRAM_BASE		CONFIG_SYS_DDR_BASE
-#define CONFIG_SYS_DDR_SDRAM_BASE	CONFIG_SYS_DDR_BASE
+#define CONFIG_SYS_SDRAM_BASE		0x00000000 /* DDR is system memory */
+#define CONFIG_SYS_DDR_SDRAM_BASE	CONFIG_SYS_SDRAM_BASE
 #define CONFIG_SYS_DDR_SDRAM_CLK_CNTL	DDR_SDRAM_CLK_CNTL_CLK_ADJUST_05
 #define CONFIG_SYS_DDRCDR_VALUE	(DDRCDR_EN \
 				| DDRCDR_PZ_LOZ \