sandbox: disable CONFIG_WATCHDOG_AUTOSTART

For the unit tests, it is more convenient if the tests are in charge
of when the watchdog devices are started and stopped, so prevent
wdt-uclass from doing it automatically.

Reviewed-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Stefan Roese <sr@denx.de>
Signed-off-by: Rasmus Villemoes <rasmus.villemoes@prevas.dk>
2 files changed