ide: remove ->dma_vendor{1,3} fields from ide_hwif_t

* Use 'hwif->dma_base + {1,3}' instead of hwif->dma_vendor{1,3} in
  pdc202xx_new host driver.

* Remove no longer needed ->dma_vendor{1,3} fields from ide_hwif_t.

Acked-by: Sergei Shtylyov <sshtylyov@ru.mvista.com>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>