libata: tell scsi layer device supports runtime power off

If ATA device supports "Device Attention", then tell scsi layer that
the device supports runtime power off.

Signed-off-by: Aaron Lu <aaron.lu@amd.com>
Signed-off-by: Lin Ming <ming.m.lin@intel.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
diff --git a/include/scsi/scsi_device.h b/include/scsi/scsi_device.h
index ba96988..aff7525 100644
--- a/include/scsi/scsi_device.h
+++ b/include/scsi/scsi_device.h
@@ -153,6 +153,7 @@
 	unsigned no_read_capacity_16:1; /* Avoid READ_CAPACITY_16 cmds */
 	unsigned try_rc_10_first:1;	/* Try READ_CAPACACITY_10 first */
 	unsigned is_visible:1;	/* is the device visible in sysfs */
+	unsigned can_power_off:1; /* Device supports runtime power off */
 
 	DECLARE_BITMAP(supported_events, SDEV_EVT_MAXBITS); /* supported events */
 	struct list_head event_list;	/* asserted events */