Fix Error while `get_input_embeddings()`

See code in [transformers](https://github.com/huggingface/transformers/blob/0963229e287501bed52ae1dabc17922524de6992/src/transformers/modeling_utils.py#L1789)

modeling_internvl_chat.py

@@ -35,6 +35,7 @@ def version_cmp(v1, v2, op='eq'):
 class InternVLChatModel(PreTrainedModel):
     config_class = InternVLChatConfig
     main_input_name = 'pixel_values'
+    base_model_prefix = 'language_model'
     _supports_flash_attn_2 = True
     _no_split_modules = ['InternVisionModel', 'LlamaDecoderLayer', 'InternLM2DecoderLayer']