IB/core: add RW API support for signature MRs

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Doug Ledford <dledford@redhat.com>
diff --git a/include/rdma/ib_verbs.h b/include/rdma/ib_verbs.h
index dd8e15d..544c55b 100644
--- a/include/rdma/ib_verbs.h
+++ b/include/rdma/ib_verbs.h
@@ -1435,6 +1435,7 @@
 	spinlock_t		mr_lock;
 	int			mrs_used;
 	struct list_head	rdma_mrs;
+	struct list_head	sig_mrs;
 	struct ib_srq	       *srq;
 	struct ib_xrcd	       *xrcd; /* XRC TGT QPs only */
 	struct list_head	xrcd_list;