dt-bindings: usb: qcom,dwc3: Document X1E80100 MP controller

The X1E80100, just like its predecessors, has a Multiport controller.
This time around, 2 HS (eUSB) and 2 SS PHYs are attached.

Document it.

Reviewed-by: Krzysztof Kozlowski <[e-mail]>
Signed-off-by: Konrad Dybcio <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Greg Kroah-Hartman <[e-mail]>

Documentation/devicetree/bindings/usb/qcom,dwc3.yaml

···
           - qcom,sm8550-dwc3
           - qcom,sm8650-dwc3
           - qcom,x1e80100-dwc3
+          - qcom,x1e80100-dwc3-mp
       - const: qcom,dwc3
 
   reg:
···
               - qcom,sc8280xp-dwc3
               - qcom,sc8280xp-dwc3-mp
               - qcom,x1e80100-dwc3
+              - qcom,x1e80100-dwc3-mp
     then:
       properties:
         clocks:
···
           contains:
             enum:
               - qcom,sc8180x-dwc3-mp
+              - qcom,x1e80100-dwc3-mp
     then:
       properties:
         interrupts: