ARM: mxs: ocotp: Fix sparse warning

Include <mach/common.h> header to fix the following sparse warning:

arch/arm/mach-mxs/ocotp.c:33:11: warning: symbol 'mxs_get_ocotp' was not declared. Should it be static?
Signed-off-by: NFabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: NShawn Guo <shawn.guo@linaro.org>

arch/arm/mach-mxs/ocotp.c

@@ -19,6 +19,7 @@
 #include <asm/processor.h>	/* for cpu_relax() */
 
 #include <mach/mxs.h>
+#include <mach/common.h>
 
 #define OCOTP_WORD_OFFSET		0x20
 #define OCOTP_WORD_COUNT		0x20