ide: add ->exec_command method

Add ->exec_command method for writing ATA Command register
and use it instead of ->OUTBSYNC.

There should be no functional changes caused by this patch.

Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
diff --git a/drivers/ide/ide-io.c b/drivers/ide/ide-io.c
index 661b75a..ca0c04a 100644
--- a/drivers/ide/ide-io.c
+++ b/drivers/ide/ide-io.c
@@ -437,8 +437,7 @@
 
 	if (ide_read_status(drive) & (BUSY_STAT | DRQ_STAT))
 		/* force an abort */
-		hwif->OUTBSYNC(hwif, WIN_IDLEIMMEDIATE,
-			       hwif->io_ports.command_addr);
+		hwif->exec_command(hwif, WIN_IDLEIMMEDIATE);
 
 	if (rq->errors >= ERROR_MAX) {
 		ide_kill_rq(drive, rq);