mpc83xx: Get rid of CONFIG_SYS_DDR_SDRAM_BASE

CONFIG_SYS_DDR_SDRAM_BASE is set to the same value as
CONFIG_SYS_SDRAM_BASE on all existing boards. Just use
CONFIG_SYS_SDRAM_BASE instead.

Signed-off-by: Mario Six <mario.six@gdsys.cc>
diff --git a/drivers/ddr/fsl/main.c b/drivers/ddr/fsl/main.c
index 6d018fd..e1f69a1 100644
--- a/drivers/ddr/fsl/main.c
+++ b/drivers/ddr/fsl/main.c
@@ -23,8 +23,12 @@
  * 0x80_8000_0000 ~ 0xff_ffff_ffff
  */
 #ifndef CONFIG_SYS_FSL_DDR_SDRAM_BASE_PHY
+#ifdef CONFIG_MPC83xx
+#define CONFIG_SYS_FSL_DDR_SDRAM_BASE_PHY CONFIG_SYS_SDRAM_BASE
+#else
 #define CONFIG_SYS_FSL_DDR_SDRAM_BASE_PHY CONFIG_SYS_DDR_SDRAM_BASE
 #endif
+#endif
 
 #ifdef CONFIG_PPC
 #include <asm/fsl_law.h>