ide: add missing checks for control register existence

Add missing checks for control register existence (some legacy m68k specific
IDE controllers don't have it).  Also use drive->ctl while at it.

Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
diff --git a/drivers/ide/ide-probe.c b/drivers/ide/ide-probe.c
index ee848c7..bd0a600 100644
--- a/drivers/ide/ide-probe.c
+++ b/drivers/ide/ide-probe.c
@@ -667,7 +667,8 @@
 		/* Ignore disks that we will not probe for later. */
 		if (!drive->noprobe || drive->present) {
 			SELECT_DRIVE(drive);
-			hwif->OUTB(8, hwif->io_ports[IDE_CONTROL_OFFSET]);
+			if (IDE_CONTROL_REG)
+				hwif->OUTB(drive->ctl, IDE_CONTROL_REG);
 			mdelay(2);
 			rc = ide_wait_not_busy(hwif, 35000);
 			if (rc)