- Add definition for SActive register
- Add most interrupt sources to default interrupt mask
- Write low 32 bits of FIS address to PxFB, where they belong
- Set command active bit in PxSACT before setting command issue bit in PxCI
- Announce Sub Class Code in driver info message [IDE, SATA or RAID]

and additionally, from me [jgarzik]:
- ignore ports-implemented bitmap for now; it's a write-only register
  that silly BIOSen initialize incorreclty
Signed-off-by: Matthijs Melchior <mmelchior@xs4all.nl>
Signed-off-by: Jeff Garzik <jgarzik@pobox.com>