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/siimage.c b/drivers/ide/pci/siimage.c
index 47b9b94..63a8a93 100644
--- a/drivers/ide/pci/siimage.c
+++ b/drivers/ide/pci/siimage.c
@@ -189,7 +189,7 @@
 
 	/* trim *taskfile* PIO to the slowest of the master/slave */
 	if (pair->present) {
-		u8 pair_pio = ide_get_best_pio_mode(pair, 255, 4, NULL);
+		u8 pair_pio = ide_get_best_pio_mode(pair, 255, 4);
 
 		if (pair_pio < tf_pio)
 			tf_pio = pair_pio;
@@ -221,7 +221,7 @@
 
 static void sil_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);
 	sil_tune_pio(drive, pio);
 	(void)ide_config_drive_speed(drive, XFER_PIO_0 + pio);
 }