Three-model pipeline became default pipeline

Author: AsyaPronina

src/plugins/intel_npu/src/plugin/npuw/llm_compiled_model.cpp

@@ -973,6 +973,12 @@ void merge_config_with(ov::AnyMap& lhs, const ov::AnyMap& rhs) {
     }
 }
 
+void update_config(ov::AnyMap& config, const std::pair<std::string, ov::Any>& pair) {
+    if (config.count(pair.first) == 0) {
+        config.insert(pair);
+    }
+}
+
 void split_llm_properties(const ov::AnyMap& properties, ov::AnyMap& llm_properties, ov::AnyMap& other_properties) {
     for (auto it = properties.begin(); it != properties.end(); ++it) {
         if (it->first.find("NPUW_LLM") != it->first.npos) {
@@ -1006,7 +1012,10 @@ ov::npuw::LLMCompiledModel::LLMCompiledModel(const std::shared_ptr<ov::Model>& m
 
     ov::AnyMap npuw_llm_props;
     ov::AnyMap other_props;
+
     split_llm_properties(properties, npuw_llm_props, other_props);
+    update_config(npuw_llm_props, {"NPUW_LLM_SHARED_HEAD", "YES"});
+
     // Solely used for serialization at the moment
     m_non_llm_props = other_props;