ide: add drive->pio_mode field

Add pio_mode field to ide_drive_t matching pio_mode field used in
struct ata_device.

The validity of the field is restricted to ->set_pio_mode method
only currently in IDE subsystem.

Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/ide/ide-devsets.c b/drivers/ide/ide-devsets.c
index 1099bf7..cb3341c 100644
--- a/drivers/ide/ide-devsets.c
+++ b/drivers/ide/ide-devsets.c
@@ -105,6 +105,8 @@
 		return -ENOSYS;
 
 	if (set_pio_mode_abuse(drive->hwif, arg)) {
+		drive->pio_mode = arg + XFER_PIO_0;
+
 		if (arg == 8 || arg == 9) {
 			unsigned long flags;