llama : MTP support for DeepSeek V3.2 (#26457)

* llama : MTP support for DeepSeek V3.2

* model : no need to include MTP layers during DeepSeek V3.2 model type discovery

---------

Co-authored-by: Stanisław Szymczyk <sszymczy@gmail.com>

src/models/models.h

@@ -1097,6 +1097,10 @@ struct llama_model_deepseek32 : public llama_model_base {
         graph(const llama_model & model, const llm_graph_params & params);
     };
 
+    struct graph_mtp : public llm_graph_context {
+        graph_mtp(const llama_model & model, const llm_graph_params & params);
+    };
+
     std::unique_ptr<llm_graph_context> build_arch_graph(const llm_graph_params & params) const override;
 };