dt-bindings: net: fec: add power-domains property

Add optional power domains property
Signed-off-by: Peng Fan <peng.fan@nxp.com>
Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://lore.kernel.org/r/20230328061518.1985981-1-peng.fan@oss.nxp.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

Documentation/devicetree/bindings/net/fsl,fec.yaml

@@ -144,6 +144,9 @@ properties:
     description:
       Regulator that powers the Ethernet PHY.
 
+  power-domains:
+    maxItems: 1
+
   fsl,num-tx-queues:
     $ref: /schemas/types.yaml#/definitions/uint32
     description: