dt-bindings: phy: usb-snps-femto-v2: Add regulator entries to example

Fix errors reported by dt_binding_check, due to missing required
regulators in the example node.

Fixes: f06b9fc9 ("dt-bindings: phy: Add binding for qcom,usb-snps-femto-v2")
Signed-off-by: Wesley Cheng <wcheng@codeaurora.org>
Reported-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/1588753589-22673-1-git-send-email-wcheng@codeaurora.orgSigned-off-by: Vinod Koul <vkoul@kernel.org>

Documentation/devicetree/bindings/phy/qcom,usb-snps-femto-v2.yaml

@@ -72,5 +72,9 @@ examples:
         clock-names = "ref";
 
         resets = <&gcc GCC_QUSB2PHY_PRIM_BCR>;
+
+        vdda-pll-supply = <&vdd_usb_hs_core>;
+        vdda33-supply = <&vdda_usb_hs_3p1>;
+        vdda18-supply = <&vdda_usb_hs_1p8>;
     };
 ...