ide: ide_id_has_flush_cache() -> ata_id_flush_enabled()

* Add ata_id_flush_enabled() inline helper to <linux/ata.h>.

* ide_id_has_flush_cache() -> ata_id_flush_enabled()

  The latter one also checks if the command is marked as
  supported in word 83 and validity of words 83 & 86.

Cc: Jeff Garzik <jgarzik@pobox.com>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
diff --git a/drivers/ide/ide-io.c b/drivers/ide/ide-io.c
index 99e0bbc..c159617 100644
--- a/drivers/ide/ide-io.c
+++ b/drivers/ide/ide-io.c
@@ -184,7 +184,7 @@
 		if (drive->media != ide_disk)
 			break;
 		/* Not supported? Switch to next step now. */
-		if (!drive->wcache || !ide_id_has_flush_cache(drive->id)) {
+		if (!drive->wcache || ata_id_flush_enabled(drive->id) == 0) {
 			ide_complete_power_step(drive, rq, 0, 0);
 			return ide_stopped;
 		}