arm/imx2x: removes a bunch of sparse-warnings

Here are some of the warnings that get fixed by this:

> 200 times: warning: cast adds address space to expression (<asn:2>)
twelve times: warning: symbol 'xxx' was not declared. Should it be static
two times: warning: symbol 'clock' shadows an earlier one
five times: warning: incorrect type in initializer (different address spaces)

Signed-off-by: Holger Schurig <hs4233@mail.mn-solutions.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

arch/arm/mach-mx2/serial.c

@@ -22,6 +22,7 @@
 #include <linux/serial.h>
 #include <mach/hardware.h>
 #include <mach/imx-uart.h>
+#include "devices.h"
 
 static struct resource uart0[] = {
 	{