dt-bindings: phy: qcom,edp-phy: allow power-domains

At least on SC8280XP the eDP PHY is part of power domain:

  sc8280xp-crd.dtb: phy@220c2a00: 'power-domains' does not match any of the regexes: 'pinctrl-[0-9]+'
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Reviewed-by: Bjorn Andersson <andersson@kernel.org>
Reviewed-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20230416151233.346336-1-krzysztof.kozlowski@linaro.orgSigned-off-by: Vinod Koul <vkoul@kernel.org>

Documentation/devicetree/bindings/phy/qcom,edp-phy.yaml

@@ -43,6 +43,9 @@ properties:
   "#phy-cells":
     const: 0
 
+  power-domains:
+    maxItems: 1
+
   vdda-phy-supply: true
   vdda-pll-supply: true