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/it821x.c b/drivers/ide/pci/it821x.c
index faccb2d..790233d 100644
--- a/drivers/ide/pci/it821x.c
+++ b/drivers/ide/pci/it821x.c
@@ -255,7 +255,7 @@
 	 * on the cable.
 	 */
 	if (pair) {
-		u8 pair_pio = ide_get_best_pio_mode(pair, 255, 4, NULL);
+		u8 pair_pio = ide_get_best_pio_mode(pair, 255, 4);
 		/* trim PIO to the slowest of the master/slave */
 		if (pair_pio < set_pio)
 			set_pio = pair_pio;
@@ -276,7 +276,7 @@
 
 static void it821x_tuneproc(ide_drive_t *drive, u8 pio)
 {
-	pio = ide_get_best_pio_mode(drive, pio, 4, NULL);
+	pio = ide_get_best_pio_mode(drive, pio, 4);
 	(void)it821x_tunepio(drive, pio);
 }