regulator: dt-bindings: qcom,qca6390-pmu: document the swctrl-gpios property

Add support for the swctrl-gpios property which contains the phandle to
the GPIO indicating the clock supply to the BT module.
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Link: https://patch.msgid.link/20240813185827.154779-3-brgl@bgdev.plSigned-off-by: Mark Brown <broonie@kernel.org>

Documentation/devicetree/bindings/regulator/qcom,qca6390-pmu.yaml

@@ -68,6 +68,10 @@ properties:
     maxItems: 1
     description: GPIO line enabling the Bluetooth module supplied by the PMU
 
+  swctrl-gpios:
+    maxItems: 1
+    description: GPIO line indicating the state of the clock supply to the BT module
+
   clocks:
     maxItems: 1
     description: Reference clock handle