libata: detect Device Attention support

Add a new flag ATA_DFLAG_DA to indicate that device supports "Device
Attention".

Acked-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>

drivers/ata/libata-core.c

diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c
index 7705191..c14f88c 100644
--- a/drivers/ata/libata-core.c
+++ b/drivers/ata/libata-core.c
@@ -2374,6 +2374,9 @@
 			dma_dir_string = ", DMADIR";
 		}
 
+		if (ata_id_has_da(dev->id))
+			dev->flags |= ATA_DFLAG_DA;
+
 		/* print device info to dmesg */
 		if (ata_msg_drv(ap) && print_info)
 			ata_dev_info(dev,