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/cmd640.c b/drivers/ide/pci/cmd640.c
index 3354829..9689494 100644
--- a/drivers/ide/pci/cmd640.c
+++ b/drivers/ide/pci/cmd640.c
@@ -766,6 +766,7 @@
 	       cmd_hwif0->name, 'a' + cmd640_chip_version - 1, bus_type, cfr);
 	cmd_hwif0->chipset = ide_cmd640;
 #ifdef CONFIG_BLK_DEV_CMD640_ENHANCED
+	cmd_hwif0->pio_mask = ATA_PIO5;
 	cmd_hwif0->tuneproc = &cmd640_tune_drive;
 #endif /* CONFIG_BLK_DEV_CMD640_ENHANCED */
 
@@ -821,6 +822,7 @@
 		cmd_hwif1->mate = cmd_hwif0;
 		cmd_hwif1->channel = 1;
 #ifdef CONFIG_BLK_DEV_CMD640_ENHANCED
+		cmd_hwif1->pio_mask = ATA_PIO5;
 		cmd_hwif1->tuneproc = &cmd640_tune_drive;
 #endif /* CONFIG_BLK_DEV_CMD640_ENHANCED */
 	}