watchdog: stop wdd when watchdog hw running in reboot_notifier

In watchdog_reboot_notifier, wdd should be stopped when the device
is in hw_running state

Signed-off-by: Zhao Qiang <qiang.zhao@nxp.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Link: https://lore.kernel.org/r/20210114082651.17162-1-qiang.zhao@nxp.com


Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@linux-watchdog.org>