dt-bindings: remoteproc: qcom,adsp: enforce smd-edge schema

The smd-edge child node references respective schema which allows
additional properties, so the ADSP needs to further restrict them.

Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://lore.kernel.org/r/20220906121358.302894-1-krzysztof.kozlowski@linaro.org


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