intel-mid_wdt: make sure watchdog is not running at startup

Make sure that the watchdog is not running after loading
and before it is started by opening /dev/watchdog.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>