dt-bindings: usb: connector: disallow additional properties

USB connector bindings is complete, thus no additional properties should
be allowed.  Add missing 'reg' property and change additionalProperties
to false, so the schema will check for anything unexpected.  This also
allows to drop the 'reg' from other bindings referencing the
usb-connector.yaml and make it required.

Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://lore.kernel.org/r/20230725102325.76336-1-krzysztof.kozlowski@linaro.org


Signed-off-by: Rob Herring <robh@kernel.org>