dt-bindings: usb: Add bindings for multiport properties on DWC3 controller

Add bindings to indicate properties required to support multiport
on Synopsys DWC3 controller.

Signed-off-by: Krishna Kurapati <[e-mail]>
Reviewed-by: Bjorn Andersson <[e-mail]>
Reviewed-by: Johan Hovold <[e-mail]>
Reviewed-by: Krzysztof Kozlowski <[e-mail]>
Tested-by: Johan Hovold <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Greg Kroah-Hartman <[e-mail]>

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

···
 
   phys:
     minItems: 1
-    maxItems: 2
+    maxItems: 19
 
   phy-names:
     minItems: 1
-    maxItems: 2
-    items:
-      enum:
-        - usb2-phy
-        - usb3-phy
+    maxItems: 19
+    oneOf:
+      - items:
+          enum: [ usb2-phy, usb3-phy ]
+      - items:
+          pattern: "^usb(2-([0-9]|1[0-4])|3-[0-3])$"
 
   power-domains:
     description: