watchdog: wdat_wdt: Ping the watchdog on resume

It turns out we need to ping the watchdog hardware on resume when we
re-program it. Otherwise this causes inadvertent reset to trigger
right after the resume is complete.

Fixes: 058dfc76

 (ACPI / watchdog: Add support for WDAT hardware watchdog)
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Acked-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>