dt-bindings: pinctrl: qcom,msm8660: convert to dtschema

dt-bindings: pinctrl: qcom,msm8660: convert to dtschema

Convert Qualcomm MSM8660 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>
Reviewed-by: Bjorn Andersson <andersson@kernel.org>
Link: https://lore.kernel.org/r/20221107185931.22075-1-krzysztof.kozlowski@linaro.org
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>