dt-bindings: usb: dwc2: Add some missing Lantiq variants

These IP block variants appear in various vendor trees and
are distinct variants which needs to be handled.

Cc: [e-mail]
Signed-off-by: Linus Walleij <[e-mail]>
Acked-by: Rob Herring <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Greg Kroah-Hartman <[e-mail]>

Documentation/devicetree/bindings/usb/dwc2.yaml

···
           - const: rockchip,rk3066-usb
           - const: snps,dwc2
       - const: lantiq,arx100-usb
+      - const: lantiq,ase-usb
+      - const: lantiq,danube-usb
       - const: lantiq,xrx200-usb
+      - const: lantiq,xrx300-usb
       - items:
           - enum:
               - amlogic,meson8-usb