sk98lin: remove obsolete driver

All the hardware supported by this driver is now supported
by the skge driver. The last remaining issue was support for ancient
dual port SysKonnect fiber boards, and the skge driver now does these
correctly (p.s. sk98lin was always broken on these old dual port
boards anyway).

Signed-off-by: Stephen Hemminger <shemminger@linux-foundation.org>
Signed-off-by: Jeff Garzik <jeff@garzik.org>