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/cmd64x.c b/drivers/ide/pci/cmd64x.c
index c383f6d..9cf969b 100644
--- a/drivers/ide/pci/cmd64x.c
+++ b/drivers/ide/pci/cmd64x.c
@@ -226,7 +226,7 @@
 	static const u8 setup_values[] = {0x40, 0x40, 0x40, 0x80, 0, 0xc0};
 	static const u8 arttim_regs[4] = {ARTTIM0, ARTTIM1, ARTTIM23, ARTTIM23};
 
-	pio_mode = ide_get_best_pio_mode(drive, mode_wanted, 5, NULL);
+	pio_mode = ide_get_best_pio_mode(drive, mode_wanted, 5);
 	cycle_time = ide_pio_cycle_time(drive, pio_mode);
 
 	cmdprintk("%s: PIO mode wanted %d, selected %d (%d ns)\n",