ARM: imx: 3ds-debugboard: Include "3ds_debugboard.h" header file

The following build warning is seen with W=1:

warning: no previous prototype for ‘mxc_expio_init’
[-Wmissing-prototypes] int __init mxc_expio_init(u32 base, u32 intr_gpio)

Fix this warning by including "3ds_debugboard.h".
Signed-off-by: Marco Franchi <marco.franchi@nxp.com>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>

arch/arm/mach-imx/3ds_debugboard.c

@@ -20,7 +20,7 @@
 #include <linux/smsc911x.h>
 #include <linux/regulator/machine.h>
 #include <linux/regulator/fixed.h>
-
+#include "3ds_debugboard.h"
 #include "hardware.h"
 
 /* LAN9217 ethernet base address */