dt-bindings: pinctrl: qcom,msm8974: convert to dtschema

Convert Qualcomm MSM8974 pin controller bindings to DT schema.  Keep the
parsing of pin configuration subnodes consistent with other Qualcomm
schemas (children named with '-state' suffix, their children with
'-pins').

Reviewed-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20221017012225.8579-1-krzysztof.kozlowski@linaro.org


Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>