ide: keep pointer to struct device instead of struct pci_dev in ide_hwif_t

Keep pointer to struct device instead of struct pci_dev in ide_hwif_t.

While on it:
* Use *dev->dma_mask instead of pci_dev->dma_mask in ide_toggle_bounce().

There should be no functionality changes caused by this patch.

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