watchdog: dw_wdt: stop on reboot

HW running watchdogs are just watchdogs that are enabled before the
Linux driver is probed, usually by the bootloader (eg. U-Boot).

When the system is shutting down, the mechanism for keeping a HW running
watchdog pinged is also stopped, but the watchdog itself is not stopped,
causing a reset, and preventing the system from being shut down.

Opt into stopping watchdogs on reboot.

Signed-off-by: Cosmin Tanislav <cosmin.tanislav@analog.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Link: https://lore.kernel.org/r/20221118150809.102505-1-cosmin.tanislav@analog.com


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