add AsExtra() mark for layer_norm

Author: zoooo0820

paddle/fluid/operators/layer_norm_op.cc

@@ -179,16 +179,19 @@ class LayerNormOpMaker : public framework::OpProtoAndCheckerMaker {
         });
     AddAttr<bool>("use_mkldnn",
                   "(bool, default false) Only used in mkldnn kernel")
-        .SetDefault(false);
+        .SetDefault(false)
+        .AsExtra();
     AddAttr<std::string>(
         "mkldnn_data_type",
         "(string, default \"float32\"). Data type of mkldnn kernel")
         .SetDefault("float32")
-        .InEnum({"float32", "bfloat16"});
+        .InEnum({"float32", "bfloat16"})
+        .AsExtra();
     AddAttr<bool>("is_test",
                   "(bool, default false) Set to true for inference only, false "
                   "for training. Some layers may run faster when this is true.")
-        .SetDefault(false);
+        .SetDefault(false)
+        .AsExtra();
 
     AddComment(R"DOC(
 Assume feature vectors exist on dimensions