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/scc_pata.c b/drivers/ide/pci/scc_pata.c
index 2c76355..f668d23 100644
--- a/drivers/ide/pci/scc_pata.c
+++ b/drivers/ide/pci/scc_pata.c
@@ -775,6 +775,7 @@
       .autodma	= AUTODMA,				\
       .bootable	= ON_BOARD,				\
       .host_flags	= IDE_HFLAG_SINGLE,		\
+      .pio_mask		= ATA_PIO4,			\
   }
 
 static ide_pci_device_t scc_chipsets[] __devinitdata = {