* to if_arge, to make it "work";
* to the mii API, if needed;
* anything new - ie, the switch API, switch PHYs, etc.
I'd like to try and finally bring some sanity to the hardcoded PHY
mask handling in if_arge (and make it actually work for AR71xx and
AR724x - where AR71xx has one shared MDIO bus between both MACs, but
AR724x has two independent MDIO busses..)