dt-bindings: usb: qcom,dwc3: correct SDM660 clocks

SDM660 SoC has two instances of DWC3 USB controller: one supporting USB
3.0 and one supporting only up to USB 2.0.  The latter one does not use
iface clock, so allow such variant to fix dtbs_check warnings:

  sda660-inforce-ifc6560.dtb: usb@c2f8800: clocks: [[37, 48], [37, 88], [37, 89], [37, 90]] is too short
  sda660-inforce-ifc6560.dtb: usb@c2f8800: clock-names:2: 'iface' was expected
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Reviewed-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20230723141550.90223-2-krzysztof.kozlowski@linaro.orgSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

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

@@ -283,15 +283,23 @@ allOf:
     then:
       properties:
         clocks:
-          minItems: 6
+          minItems: 5
+          maxItems: 6
         clock-names:
-          items:
+          oneOf:
+            - items:
                 - const: cfg_noc
                 - const: core
                 - const: iface
                 - const: sleep
                 - const: mock_utmi
                 - const: bus
+            - items:
+                - const: cfg_noc
+                - const: core
+                - const: sleep
+                - const: mock_utmi
+                - const: bus
 
   - if:
       properties: