dt-bindings: soc: qcom: smd-rpm: allow MSM8226 over SMD

The MSM8226 RPM uses SMD, so it must allow qcom,smd-channels:

  qcom-msm8226-samsung-s3ve3g.dtb: rpm-requests: qcom,smd-channels: False schema does not allow ['rpm_requests']

Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Bjorn Andersson <andersson@kernel.org>
Link: https://lore.kernel.org/r/20230410181036.25943-1-krzysztof.kozlowski@linaro.org