Unlike most other PHYs there is no easy way to know which media
type the PHY supports on Marvell PHYs. MIIF_HAVEFIBER flags is now
passed via bus-specific instance variable of a device. While I'm
here add 88E1112 specific work around to set SIGDET polarity low.
Many thanks "Eugene Perevyazko <john <> dnepro dot net>" who kindly
gave remote access to system with DGE-560SX.