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/mpc8308_p1m/sdram.c b/board/mpc8308_p1m/sdram.c
index 4118c01..baf70d8 100644
--- a/board/mpc8308_p1m/sdram.c
+++ b/board/mpc8308_p1m/sdram.c
@@ -29,7 +29,7 @@
 	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);
 
@@ -57,7 +57,7 @@
 	setbits_be32(&im->ddr.sdram_cfg, SDRAM_CFG_MEM_EN);
 	sync();
 
-	return get_ram_size(CONFIG_SYS_DDR_SDRAM_BASE, msize);
+	return get_ram_size(CONFIG_SYS_SDRAM_BASE, msize);
 }
 
 int dram_init(void)