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/siimage.c b/drivers/ide/pci/siimage.c
index 63a8a93..50f6d17 100644
--- a/drivers/ide/pci/siimage.c
+++ b/drivers/ide/pci/siimage.c
@@ -959,6 +959,7 @@
 		.fixup		= siimage_fixup,	\
 		.autodma	= AUTODMA,		\
 		.bootable	= ON_BOARD,		\
+		.pio_mask	= ATA_PIO4,		\
 	}
 
 static ide_pci_device_t siimage_chipsets[] __devinitdata = {