dt-bindings: net: ethernet-phy: clarify when compatible must specify PHY ID

        description: PHYs that implement IEEE802.3 clause 45

      - pattern: "^ethernet-phy-id[a-f0-9]{4}\\.[a-f0-9]{4}$"

        description:

          If the PHY reports an incorrect ID (or none at all) then the

          compatible list may contain an entry with the correct PHY ID

          in the above form.

          PHYs contain identification registers. These will be read to

          identify the PHY. If the PHY reports an incorrect ID, or the

          PHY requires a specific initialization sequence (like a

          particular order of clocks, resets, power supplies), in

          order to be able to read the ID registers, then the

          compatible list must contain an entry with the correct PHY

          ID in the above form.

          The first group of digits is the 16 bit Phy Identifier 1

          register, this is the chip vendor OUI bits 3:18. The

          second group of digits is the Phy Identifier 2 register,