ide: add PIO masks

* Add ATA_PIO[0-6] defines to <linux/ata.h>.

* Add ->pio_mask field to ide_pci_device_t and ide_hwif_t.

* Add PIO masks to host drivers.

<linux/ata.h> change ACK-ed by Jeff Garzik <jeff@garzik.org>.

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

drivers/ide/legacy/umc8672.c

@@ -149,10 +149,12 @@ static int __init umc8672_probe(void)
 	mate = &ide_hwifs[1];
 
 	hwif->chipset = ide_umc8672;
+	hwif->pio_mask = ATA_PIO4;
 	hwif->tuneproc = &tune_umc;
 	hwif->mate = mate;
 
 	mate->chipset = ide_umc8672;
+	mate->pio_mask = ATA_PIO4;
 	mate->tuneproc = &tune_umc;
 	mate->mate = hwif;
 	mate->channel = 1;