IB/sa: Add ib_init_ah_from_path()

Add a call to initialize address handle attributes given a path record.
This is used by the CM, and would be useful for users of UD QPs.

Signed-off-by: Sean Hefty <sean.hefty@intel.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
diff --git a/include/rdma/ib_sa.h b/include/rdma/ib_sa.h
index ad63c21..c99e442 100644
--- a/include/rdma/ib_sa.h
+++ b/include/rdma/ib_sa.h
@@ -370,5 +370,12 @@
 					context, query);
 }
 
+/**
+ * ib_init_ah_from_path - Initialize address handle attributes based on an SA
+ *   path record.
+ */
+int ib_init_ah_from_path(struct ib_device *device, u8 port_num,
+			 struct ib_sa_path_rec *rec,
+			 struct ib_ah_attr *ah_attr);
 
 #endif /* IB_SA_H */