3C940 / Asus P4P800 gigabit LAN driver

Hi,

I ported the openbsd additions to the sk driver to support the 3c940
gigabit network card which is commonly found in the above asus
motherboard.  Testers/comments/commits welcome, but please don't blame
me if it burns your house down or something :)

Apply the diff in /usr/src/sys.  It will have to be a fairly recent
-current because of the recent pci header reloactions.

Please be aware that I have had reports of panics on kldunloading the sk
module.  I don't posess the hardware myself and this could be present in
the sk driver in general, so more information on this would be greatly
received.

Regards,

Stuart Walsh