dt-bindings: watchdog: uniphier: Use unevaluatedProperties

This refers common bindings, so this is preferred for
unevaluatedProperties instead of additionalProperties.

Signed-off-by: Kunihiko Hayashi <hayashi.kunihiko@socionext.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Link: https://lore.kernel.org/r/1649317606-21267-1-git-send-email-hayashi.kunihiko@socionext.com


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