dt-bindings: soc: qcom,smd: do not use pattern for simple rpm-requests string

patternProperties should not be used for properties with a simple string
as name:

  Documentation/devicetree/bindings/soc/qcom/qcom,smd.yaml: patternProperties:^(.*-edge|rpm)$:patternProperties:
    '^rpm-requests$' should not be valid under {'pattern': '^\\^[a-zA-Z0-9,\\-._#]+\\$$'}

Fixes: 375eed5f ("dt-bindings: soc: qcom,smd: convert to dtschema")
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20220524070408.39505-1-krzysztof.kozlowski@linaro.org