Document the compatible for RPM communication over SMD for IPQ9574 SoC Signed-off-by: Devi Priya <quic_devipriy@quicinc.com> Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org> Signed-off-by: Bjorn Andersson <andersson@kernel.org> Link: https://lore.kernel.org/r/20230217142030.16012-2-quic_devipriy@quicinc.com