[RFC PATCH v3 3/3] dt-bindings: access-controllers: Add SiFive WorldGuard Checker

[Yu-Chien Peter Lin]

> +required:
> +  - compatible
> +  - reg
> +  - "#address-cells"
> +  - "#size-cells"
> +  - "#access-controller-cells"
> +
> +additionalProperties: false

The wgChecker is always an access-controller provider, never a
consumer. Using additionalProperties:false prevents consumer-side
properties (access-controllers, access-controller-names) from
appearing on a wgChecker node, which unevaluatedProperties:false
would not.