I am thinking about merging this into the switch driver, then we do not
have to configure the dependency any more.

Hi Hauke

Are there any PHYs which are not part of the switch?

Making it part of the switch driver would make sense. Are there any
backwards compatibility issues? I don't actually see any boards in
mailine using the compatible strings.

Another option would be to write an independent mdio driver, and make
firmware download part of that. That gives the advantage of supporting
PHYs which are not part of the switch.

     Andrew