dt-bindings: display: msm: sm8650-mdss: Add missing explicit "additionalProperties"

In order to check schemas for missing additionalProperties or
unevaluatedProperties, cases allowing extra properties must be explicit.

Signed-off-by: Rob Herring <robh@kernel.org>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Patchwork: https://patchwork.freedesktop.org/patch/576954/
Link: https://lore.kernel.org/r/20240202222338.1652333-1-robh@kernel.org


Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>