ahci: EM message type auto detect

Detect enclosure management message type automatically at driver
initialization, instead of using module parameter "ahci_em_messages".

Signed-off-by: Harry Zhang <harry.zhang@amd.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
diff --git a/drivers/ata/ahci.c b/drivers/ata/ahci.c
index c44d112..8ca16f5 100644
--- a/drivers/ata/ahci.c
+++ b/drivers/ata/ahci.c
@@ -1185,7 +1185,7 @@
 
 		/* set enclosure management message type */
 		if (ap->flags & ATA_FLAG_EM)
-			ap->em_message_type = ahci_em_messages;
+			ap->em_message_type = hpriv->em_msg_type;
 
 
 		/* disabled/not-implemented port */