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/opti621.c b/drivers/ide/pci/opti621.c
index 78d7adf..1802ad0 100644
--- a/drivers/ide/pci/opti621.c
+++ b/drivers/ide/pci/opti621.c
@@ -147,12 +147,12 @@
 	int d;
 	ide_hwif_t *hwif = HWIF(drive);
 
-	drive->drive_data = ide_get_best_pio_mode(drive, pio, OPTI621_MAX_PIO, NULL);
+	drive->drive_data = ide_get_best_pio_mode(drive, pio, OPTI621_MAX_PIO);
 	for (d = 0; d < 2; ++d) {
 		drive = &hwif->drives[d];
 		if (drive->present) {
 			if (drive->drive_data == PIO_DONT_KNOW)
-				drive->drive_data = ide_get_best_pio_mode(drive, 255, OPTI621_MAX_PIO, NULL);
+				drive->drive_data = ide_get_best_pio_mode(drive, 255, OPTI621_MAX_PIO);
 #ifdef OPTI621_DEBUG
 			printk("%s: Selected PIO mode %d\n",
 				drive->name, drive->drive_data);