HEADSUP! SATA PHY code added for nVidia, SiS and VIA chips

As the subject says I've added support for for the SATA PHY (the serial 
link interface HW) to -current. This is needed to sort out problems with 
the connection and on those chipsets that support its, handle hotplug.

At any rate, since I dont have any of these chipsets in the lab the code 
was done blindfolded from docs, so it needs testing and quite possibly 
bugfixing as well.

Please report of any success/failures, and in both cases the output from 
dmesg would be handy, as well as knowing if software inititated 
detach/attach via atacontrol works, and on the nVidia if even hotplug is 
possible...

Thanks!

-- 

-Søren