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

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.org
Signed-off-by: Vinod Koul <vkoul@kernel.org>