dt-bindings: clock: qcom,kaanapali-gxclkctl: Correctly use additionalProperties

dt-bindings: clock: qcom,kaanapali-gxclkctl: Correctly use additionalProperties

The binding does not reference any other schema, thus should use
"additionalProperties: false" to disallow any undocumented properties.

Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@oss.qualcomm.com>
Acked-by: Rob Herring (Arm) <robh@kernel.org>
Reviewed-by: Taniya Das <taniya.das@oss.qualcomm.com>
Link: https://lore.kernel.org/r/20260404105436.138110-2-krzysztof.kozlowski@oss.qualcomm.com
Signed-off-by: Bjorn Andersson <andersson@kernel.org>