ColdFire: uart: fix build failure for missing header files

The following commit introduces some build failures for ColdFire
platform.

commit abaef69fbe
Author: Marek Vasut <marex@denx.de>
Date:   Thu Sep 13 16:51:38 2012 +0200

Add the missed header files.

Sign-off-by: Alison Wang <b18965@freescale.com>

drivers/serial/mcfuart.c

@@ -28,6 +28,8 @@
  */
 
 #include <common.h>
+#include <serial.h>
+#include <linux/compiler.h>
 
 #include <asm/immap.h>
 #include <asm/uart.h>