dt-bindings: pinctrl: qcom,msm8976: convert to dtschema

dt-bindings: pinctrl: qcom,msm8976: convert to dtschema

Convert Qualcomm MSM8976 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').

Changes during conversion: update the list of non-mux pins (like sdc1)
to match Linux driver.

Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Marijn Suijten <marijn.suijten@somainline.org>
Link: https://lore.kernel.org/r/20221110085230.15108-1-krzysztof.kozlowski@linaro.org
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>