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/pci/cs5535.c

@@ -231,6 +231,7 @@ static ide_pci_device_t cs5535_chipset __devinitdata = {
 	.autodma	= AUTODMA,
 	.bootable	= ON_BOARD,
 	.host_flags	= IDE_HFLAG_SINGLE,
+	.pio_mask	= ATA_PIO4,
 };
 
 static int __devinit cs5535_init_one(struct pci_dev *dev,