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>
diff --git a/drivers/ide/pci/slc90e66.c b/drivers/ide/pci/slc90e66.c
index 562747f..8e655f2 100644
--- a/drivers/ide/pci/slc90e66.c
+++ b/drivers/ide/pci/slc90e66.c
@@ -217,6 +217,7 @@
 	.autodma	= AUTODMA,
 	.enablebits	= {{0x41,0x80,0x80}, {0x43,0x80,0x80}},
 	.bootable	= ON_BOARD,
+	.pio_mask	= ATA_PIO4,
 };
 
 static int __devinit slc90e66_init_one(struct pci_dev *dev, const struct pci_device_id *id)