dt-bindings: pinctrl: qcom,pmic-gpio: add PMI632

Document the 8 GPIOs found on PMI632.

Signed-off-by: Luca Weiss <luca@z3ntu.xyz>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://lore.kernel.org/r/20230414-pmi632-v2-1-98bafa909c36@z3ntu.xyz


Signed-off-by: Linus Walleij <linus.walleij@linaro.org>