dt-bindings: usb: add rk3588 compatible to rockchip,dwc3

RK3588 has three DWC3 controllers. Two of them are fully functional in
host, device and OTG mode including USB2 support. They are connected to
dedicated PHYs, that also support USB-C's DisplayPort alternate mode.

The third controller is connected to one of the combphy's shared
with PCIe and SATA. It can only be used in host mode and does not
support USB2. Compared to the other controllers this one needs
some extra clocks.

Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>

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

@@ -30,6 +30,7 @@ select:
         enum:
           - rockchip,rk3328-dwc3
           - rockchip,rk3568-dwc3
+          - rockchip,rk3588-dwc3
   required:
     - compatible
 
@@ -39,6 +40,7 @@ properties:
       - enum:
           - rockchip,rk3328-dwc3
           - rockchip,rk3568-dwc3
+          - rockchip,rk3588-dwc3
       - const: snps,dwc3
 
   reg:
@@ -58,7 +60,9 @@ properties:
           Master/Core clock, must to be >= 62.5 MHz for SS
           operation and >= 30MHz for HS operation
       - description:
-          Controller grf clock
+          Controller grf clock OR UTMI clock
+      - description:
+          PIPE clock
 
   clock-names:
     minItems: 3
@@ -66,7 +70,10 @@ properties:
       - const: ref_clk
       - const: suspend_clk
       - const: bus_clk
-      - const: grf_clk
+      - enum:
+          - grf_clk
+          - utmi
+      - const: pipe
 
   power-domains:
     maxItems: 1