ide: add ide_retry_pc() helper

ide: add ide_retry_pc() helper

* Add ide_create_request_sense_cmd() and ide_retry_pc() helpers
  and convert ide-{atapi,floppy,tape}.c to use them.

* Remove no longer used ide*_create_request_sense_cmd(),
  ide*_retry_pc() and 'retry_pc' argument from ide_pc_intr().

* Make ide_queue_pc_head() static.

There should be no functional changes caused by this patch.

Cc: Borislav Petkov <petkovbb@gmail.com>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>