Add LLaDA-7b-MoE diffusion model (#16003)

src/llama-arch.h

@@ -100,6 +100,7 @@ enum llm_arch {
     LLM_ARCH_DREAM,
     LLM_ARCH_SMALLTHINKER,
     LLM_ARCH_LLADA,
+    LLM_ARCH_LLADA_MOE,
     LLM_ARCH_SEED_OSS,
     LLM_ARCH_UNKNOWN,
 };