ide: remove ->dma_master field from ide_hwif_t (take 5)

ide: remove ->dma_master field from ide_hwif_t (take 5)

* Convert cmd64x, hpt366 and pdc202xx_old host drivers to use
  pci_resource_start(hwif->pci_dev, 4) instead of hwif->dma_master.

* Remove no longer needed ->dma_master field from ide_hwif_t.

v2:
* Use the more readable 'hwif->dma_base - (hwif->channel * 8)' instead of
  pci_resource_start(hwif->pci_dev, 4).

v3:
* Use hwif->extra_base in hpt366/pdc20xx_old + some cosmetic fixups over v2
  (suggested by Sergei).

v4:
* Correct offsets in hpt3xxn_set_clock().

v5:
* Use hwif->extra_base in hpt366 for _real_ this time. (Noticed by Sergei)

Acked-by: Sergei Shtylyov <sshtylyov@ru.mvista.com>
Cc: Jeff Garzik <jeff@garzik.org>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>