Remove compat shims for FreeBSD versions older than 8.0.

Reviewed by:	Steve Chang <ychang@highpoint-tech.com>
Various fixes to hptiop(4):
- Use callout(9) instead of timeout(9).
- Use the existing hba lock as the CAM sim lock instead of Giant.
- Mark interrupt handler MPSAFE.
- Reorder detach and destroy the hba lock in detach.

Reviewed by:	Steve Chang <ychang@highpoint-tech.com>
Various fixes to hptnr(4):
- Use the existing vbus locks instead of Giant for the CAM sim lock.
- Use callout(9) instead of timeout(9).
- Mark the interrupt handler MPSAFE.
- Don't attempt to pass data in the softc from probe() to attach().
- Remove compat shims for FreeBSD versions older than 8.0.

Reviewed by:	Steve Chang <ychang@highpoint-tech.com>