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/board/ids/ids8313/ids8313.c b/board/ids/ids8313/ids8313.c
index a37ca8a..a66234a 100644
--- a/board/ids/ids8313/ids8313.c
+++ b/board/ids/ids8313/ids8313.c
@@ -57,7 +57,7 @@
 	u32 msize_log2 = __ilog2(msize);
 
 	out_be32(&im->sysconf.ddrlaw[0].bar,
-		 (CONFIG_SYS_DDR_SDRAM_BASE & 0xfffff000));
+		 (CONFIG_SYS_SDRAM_BASE & 0xfffff000));
 	out_be32(&im->sysconf.ddrlaw[0].ar, LBLAWAR_EN | (msize_log2 - 1));
 	out_be32(&im->sysconf.ddrcdr, CONFIG_SYS_DDRCDR_VALUE);
 	sync();