ColdFire:Add mb for 5253 dram initialization

The dram initialization sequence should be in order.
This patch add mb for the dram intialization code to make
sure the compiler do not disorder the code.

Signed-off-by: Jason Jin <Jason.jin@freescale.com>
diff --git a/board/freescale/m5253demo/m5253demo.c b/board/freescale/m5253demo/m5253demo.c
index 4772074..8ffb2cc 100644
--- a/board/freescale/m5253demo/m5253demo.c
+++ b/board/freescale/m5253demo/m5253demo.c
@@ -27,6 +27,7 @@
 #include <common.h>
 #include <asm/immap.h>
 #include <netdev.h>
+#include <asm/io.h>
 
 int checkboard(void)
 {
@@ -63,10 +64,12 @@
 		__asm__("nop");
 
 		mbar_writeLong(MCFSIM_DACR0, 0x0000322c);
+		mb();
 		__asm__("nop");
 
 		/* Write to this block to initiate precharge */
 		*(u32 *) (CONFIG_SYS_SDRAM_BASE) = 0xa5a5a5a5;
+		mb();
 		__asm__("nop");
 
 		/* Set RE bit in DACR */
@@ -83,6 +86,7 @@
 		__asm__("nop");
 
 		*(u32 *) (CONFIG_SYS_SDRAM_BASE + 0x800) = 0xa5a5a5a5;
+		mb();
 	}
 
 	return dramsize;