watchdog: watchdog_dev: include private header to pickup global symbol prototypes

Include the private watchdog_dev.h header to pickup the prototypes for the
watchdog_dev_register/unregister functions.

This quiets the following sparse warnings:

warning: symbol 'watchdog_dev_register' was not declared. Should it be static?
warning: symbol 'watchdog_dev_unregister' was not declared. Should it be static?
Signed-off-by: NH Hartley Sweeten <hsweeten@visionengravers.com>
Signed-off-by: NWim Van Sebroeck <wim@iguana.be>

drivers/watchdog/watchdog_dev.c

@@ -42,6 +42,8 @@
 #include <linux/init.h>		/* For __init/__exit/... */
 #include <linux/uaccess.h>	/* For copy_to_user/put_user/... */
 
+#include "watchdog_dev.h"
+
 /* make sure we only register one /dev/watchdog device */
 static unsigned long watchdog_dev_busy;
 /* the watchdog device behind /dev/watchdog */