nvme.h: add AER constants

Reviewed-by: Jay Freyensee <james.p.freyensee@intel.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Ming Lin <ming.l@ssi.samsung.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Jens Axboe <axboe@fb.com>

include/linux/nvme.h

@@ -284,6 +284,12 @@ struct nvme_reservation_status {
 	} regctl_ds[];
 };
 
+enum nvme_async_event_type {
+	NVME_AER_TYPE_ERROR	= 0,
+	NVME_AER_TYPE_SMART	= 1,
+	NVME_AER_TYPE_NOTICE	= 2,
+};
+
 /* I/O commands */
 
 enum nvme_opcode {