Use new wd33c93_{abort,host_reset}() routines introduced in 2.5.67 in the m68k
wd33c93-based SCSI host adapter drivers:
  - Amiga A2091 SCSI
  - Amiga A3000 SCSI
  - Amiga GVP Series II SCSI
  - MVME147 SCSI

These drivers still have to implement their own adapter-specific bus_reset()
routines!