rz1000: apply chipset quirks early (v2)

* Use pci_name(dev) instead of hwif->name in init_hwif_rz1000().

* init_hwif_rz1000() -> rz1000_init_chipset().  Update rz1000_init_one()
  to use rz1000_init_chipset() and add now required rz1000_remove().

* Remove superfluous ide_rz1000 chipset type.

v2:
* unsigned int rz1000_init_chipset() -> int rz1000_disable_readahead()
  per Sergei's suggestion.

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