[Model] Support for Spark2_5ForCausalLM implementation (#27868)

* Add Spark3 Model
* rename spark3 -> spark2_5

Co-authored-by: Sigbjørn Skjæret <sigbjorn.skjaeret@huggingface.co>
Co-authored-by: dongjiang <dongjiang2010@gmail.com>

src/llama-model.cpp

@@ -338,6 +338,8 @@ static llama_model * llama_model_mapping(llm_arch arch, const llama_model_params
             return new llama_model_kimi_k3(params);
         case LLM_ARCH_STEP35:
             return new llama_model_step35(params);
+        case LLM_ARCH_SPARK2_5:
+            return new llama_model_spark2_5(params);
         default:
             throw std::runtime_error(std::string("unsupported model architecture: '") + llm_arch_name(arch) + "'");
     }
@@ -2999,6 +3001,7 @@ llama_rope_type llama_model_rope_type(const llama_model * model) {
         case LLM_ARCH_QWEN3NEXT:
         case LLM_ARCH_MIMO2:
         case LLM_ARCH_STEP35:
+        case LLM_ARCH_SPARK2_5:
         case LLM_ARCH_TALKIE:
         case LLM_ARCH_MELLUM:
             return LLAMA_ROPE_TYPE_NEOX;