dt-bindings: gpio: Convert qca,ar7100-gpio to DT schema

Convert the Qualcomm Atheros AR7xxx/AR9xxx GPIO binding to DT schema
format.

Signed-off-by: Rob Herring (Arm) <robh@kernel.org>
Link: https://lore.kernel.org/r/20250714202859.3012173-1-robh@kernel.org


Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>