Register a restart handler for the da9063 watchdog. System restart is
triggered by sending the shutdown command to the PMIC.
As more-suitable restart handlers may exist, the priority of the
watchdog restart handler is set to 128.
The actual restart method was inspired by a platform-specific patch from
the BSP by Hisashi Nakamura <hisashi.nakamura.ak@renesas.com>.
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Acked-by: Steve Twiss <stwiss.opensource@diasemi.com> Reviewed-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Wim Van Sebroeck <wim@iguana.be>