dt-bindings: usb: samsung,exynos-dwc3: allow unit address in DTS

The Samsung Exynos SoC USB 3.0 DWC3 Controller is a simple wrapper of
actual DWC3 Controller device node. It handles necessary Samsung
Exynos-specific resources (regulators, clocks), but does not have its
own MMIO address space.

However neither simple-bus bindings nor dtc W=1 accept device nodes in
soc@ node which do not have unit address.

Signed-off-by: Krzysztof Kozlowski <[e-mail]>
Reviewed-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/samsung,exynos-dwc3.yaml

···
     #include <dt-bindings/clock/exynos5420.h>
     #include <dt-bindings/interrupt-controller/arm-gic.h>
 
-    usb {
+    usb@12000000 {
         compatible = "samsung,exynos5250-dwusb3";
         #address-cells = <1>;
         #size-cells = <1>;
-        ranges;
+        ranges = <0x0 0x12000000 0x10000>;
         clocks = <&clock CLK_USBD300>;
         clock-names = "usbdrd30";
         vdd33-supply = <&ldo9_reg>;
         vdd10-supply = <&ldo11_reg>;
 
-        usb@12000000 {
+        usb@0 {
             compatible = "snps,dwc3";
-            reg = <0x12000000 0x10000>;
+            reg = <0x0 0x10000>;
             interrupts = <GIC_SPI 72 IRQ_TYPE_LEVEL_HIGH>;
             phys = <&usbdrd_phy0 0>, <&usbdrd_phy0 1>;
             phy-names = "usb2-phy", "usb3-phy";