atiixp: PIO mode setup fixes

atiixp: PIO mode setup fixes

* Split off exisiting atiixp_tuneproc() into atiixp_tune_pio()
  and then add setting device PIO mode to atiixp_tuneproc().

* Add missing ide_get_best_pio_mode() call to atiixp_tuneproc() so
  "pio" == 255 (autotune) is handled correctly and "pio" values > 4 && < 255
  are filtered to PIO4 (previously "pio" == 5 could result in wrong timings
  being used and "pio" values > 4 && < 255 in an OOPS).

* Handle PIO modes early in atiixp_speedproc() so save_mdma_mode[]
  doesn't get cleared.

* In atiixp_dma_check():
  - fix max_mode argument for ide_get_best_pio_mode()
  - don't call atiixp_dma_2_pio() so PIO1 doesn't get remapped to PIO0
  - use atiixp_tuneproc() instead of atiixp_speedproc()

* Bump driver version.

Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>