[Model] Pass param prefix to LLMHead (#24862)

Signed-off-by: whx-sjtu <2952154980@qq.com>

vllm/model_executor/models/phi4mm.py

@@ -989,6 +989,7 @@ class Phi4MMForCausalLM(nn.Module, SupportsLoRA, SupportsMultiModal):
             org_num_embeddings=config.vocab_size,
             padding_size=DEFAULT_VOCAB_PADDING_SIZE,
             quant_config=quant_config,
+            prefix=maybe_prefix(prefix, "lm_head"),
         )
         if config.tie_word_embeddings:
             self.lm_head = self.lm_head.tie_weights(self.model.embed_tokens)