ide: drop "PIO data" argument from ide_get_best_pio_mode()

* Drop no longer needed "PIO data" argument from ide_get_best_pio_mode()
  and convert all users accordingly.

* Remove no longer needed ide_pio_data_t.

Acked-by: Sergei Shtylyov <sshtylyov@ru.mvista.com>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
diff --git a/drivers/ide/pci/triflex.c b/drivers/ide/pci/triflex.c
index 801314f..f8fef90 100644
--- a/drivers/ide/pci/triflex.c
+++ b/drivers/ide/pci/triflex.c
@@ -96,7 +96,7 @@
 
 static void triflex_tune_drive(ide_drive_t *drive, u8 pio)
 {
-	int use_pio = ide_get_best_pio_mode(drive, pio, 4, NULL);
+	int use_pio = ide_get_best_pio_mode(drive, pio, 4);
 	(void) triflex_tune_chipset(drive, (XFER_PIO_0 + use_pio));
 }