fix compilation errors caused by namespace

related: #25199

modules/dnn/src/layers/elementwise_layers.cpp

@@ -932,7 +932,7 @@ struct GeluFunctor : public BaseFunctor {
 #endif
 
 #ifdef HAVE_DNN_NGRAPH
-    std::shared_ptr<ngraph::Node> initNgraphAPI(const ngraph::Output<ngraph::Node>& node)
+    std::shared_ptr<ov::Node> initNgraphAPI(const ov::Output<ov::Node>& node)
     {
         return std::make_shared<ov::op::v0::Gelu>(node);
     }

modules/dnn/src/layers/nary_eltwise_layers.cpp

@@ -1006,7 +1006,7 @@ public:
         // In case only one input
         if (inputs.size() == 1) {
             auto &ieInpNode = nodes[0].dynamicCast<InfEngineNgraphNode>()->node;
-            ngraph::OutputVector inp{ieInpNode};
+            ov::OutputVector inp{ieInpNode};
             auto blank = std::make_shared<ov::op::v0::Concat>(inp, 0);
             return Ptr<BackendNode>(new InfEngineNgraphNode(blank));
         }