- Sync with 2.5.21

 - Don't call put_device inside idedisk_cleanup(). This is apparently triggering
   some bug inside the handling of device trees. Or we don't register the device
   properly within the tree. Check this later.

 - Further work on the channel register file access locking.  Push the locking
   out from __ide_end_request to ide_end_request.  Rename those functions to
   respective __ata_end_request() and ata_end_request().

 - Move ide_wait_status to device.c rename it to ata_status_poll().

 - Further work on locking scope issues.

 - devfs showed us once again that it changed the policy from agnostic numbers
   to unpleasant string names.