dt-bindings: power: supply: qcom,pm8941: document usb-charge-current-limit

Document already used (in DTS and by driver) 'usb-charge-current-limit'
property:

  arch/arm/boot/dts/qcom-msm8974pro-fairphone-fp2.dtb:
    charger@1000: 'usb-charge-current-limit' does not match any of the regexes: 'pinctrl-[0-9]+'
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>

Documentation/devicetree/bindings/power/supply/qcom,pm8941-charger.yaml

@@ -117,6 +117,13 @@ properties:
       be done externally to fully comply with the JEITA safety guidelines if this flag
       is set.
 
+  usb-charge-current-limit:
+    $ref: /schemas/types.yaml#/definitions/uint32
+    minimum: 100000
+    maximum: 2500000
+    description: |
+      Default USB charge current limit in uA.
+
   usb-otg-in-supply:
     description: Reference to the regulator supplying power to the USB_OTG_IN pin.