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/ppc/mpc8xx.c b/drivers/ide/ppc/mpc8xx.c
index f3789c0..8859fe2 100644
--- a/drivers/ide/ppc/mpc8xx.c
+++ b/drivers/ide/ppc/mpc8xx.c
@@ -316,6 +316,7 @@
 	}
 
 	/* register routine to tune PIO mode */
+	ide_hwifs[data_port].pio_mask = ATA_PIO4;
 	ide_hwifs[data_port].tuneproc = m8xx_ide_tuneproc;
 
 	hw->ack_intr = (ide_ack_intr_t *) ide_interrupt_ack;
@@ -402,6 +403,7 @@
 	}
 
 	/* register routine to tune PIO mode */
+	ide_hwifs[data_port].pio_mask = ATA_PIO4;
 	ide_hwifs[data_port].tuneproc = m8xx_ide_tuneproc;
 
 	hw->ack_intr = (ide_ack_intr_t *) ide_interrupt_ack;