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 <[e-mail]>
Reviewed-by: Bjorn Andersson <[e-mail]>
Reviewed-by: Rob Herring <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Vinod Koul <[e-mail]>

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

···
   "#phy-cells":
     const: 0
 
+  power-domains:
+    maxItems: 1
+
   vdda-phy-supply: true
   vdda-pll-supply: true