rfkill: Fix sparse warning

#include <linux/mutex.h>

#include <linux/rfkill.h>

/* Get declaration of rfkill_switch_all() to shut up sparse. */

#include "rfkill-input.h"

MODULE_AUTHOR("Ivo van Doorn <IvDoorn@gmail.com>");

MODULE_VERSION("1.0");

MODULE_DESCRIPTION("RF switch support");