[Model] Interface to enable batch-level DP support (#23733)

Signed-off-by: DarkLight1337 <tlleungac@connect.ust.hk>
Signed-off-by: Cyrus Leung <cyrus.tl.leung@gmail.com>
Co-authored-by: gemini-code-assist[bot] <176961590+gemini-code-assist[bot]@users.noreply.github.com>

vllm/model_executor/models/step3_vl.py

@@ -867,6 +867,8 @@ class Step3VLForConditionalGeneration(nn.Module, SupportsMultiModal,
         "lm_head.": "language_model.lm_head.",
     })
 
+    supports_encoder_tp_data = True
+
     @classmethod
     def get_placeholder_str(cls, modality: str, i: int) -> Optional[str]:
         if modality.startswith("image"):