watchdog: da9062: add power management ops

Disable the watchdog during suspend if it is enabled and re-enable it on
resume. So we can sleep without the interruptions.

Signed-off-by: Marco Felsch <m.felsch@pengutronix.de>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Link: https://lore.kernel.org/r/20191128171931.22563-1-m.felsch@pengutronix.de


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