- Integrate the TCQ stuff from Jens Axboe. Deal with the conflicts, apply some
   cosmetic changes. We are still not at a stage where we could immediately
   integrate ata_request and ata_taskfile but we are no longer far away.

- Clean up the data transfer function in ide-disk to use ata_request structures
   directly.

- Kill useless leading version information in ide-disk.c

- Replace the ATA_AR_INIT macro with inline ata_ar_init() function.

- Replace IDE_CLEAR_TAG with ata_clear_tag().

- Replace IDE_SET_TAG with ata_set_tag().

- Kill georgeous ide_dmafunc_verbose().

- Fix typo in ide_enable_queued() (ide-tcq.c!)

Apparently there still problems with a TCQ enabled device and a not enabled
device on the same channel, but let's first synchronize up with Jens.