ColdFire: Fix M54451 serial boot dram setup

The serial boot dram extended/standard mode register was not
setup and was using default DRAM setup causing the U-boot was
unstable to boot up in serial mode.
Signed-off-by: NTsiChung Liew <Tsi-Chung.Liew@freescale.com>

cpu/mcf5445x/start.S

@@ -243,9 +243,9 @@ wait1000:
 	nop
 #elif defined(CONFIG_M54451EVB)
 	/* Issue LEMR */
-	move.l	#(CONFIG_SYS_SDRAM_MODE), (%a2)
+	move.l	#(CONFIG_SYS_SDRAM_MODE), (%a1)
 	nop
-	move.l	#(CONFIG_SYS_SDRAM_EMOD), (%a2)
+	move.l	#(CONFIG_SYS_SDRAM_EMOD), (%a1)
 	nop
 #endif