[Refactor] Define MM data parser in processing info instead of processor itself (#33260)

Signed-off-by: DarkLight1337 <tlleungac@connect.ust.hk>

vllm/model_executor/models/nano_nemotron_vl.py

@@ -1143,6 +1143,12 @@ class NanoNemotronVLProcessingInfo(BaseNanoNemotronVLProcessingInfo):
     def supports_video(self):
         return self.get_hf_processor().supports_video
 
+    def get_data_parser(self):
+        return MultiModalDataParser(
+            video_needs_metadata=True,
+            expected_hidden_size=self._get_expected_hidden_size(),
+        )
+
     def get_supported_mm_limits(self):
         video_limit = {"video": None} if self.supports_video else {}
         return {**super().get_supported_mm_limits(), **video_limit}
@@ -1274,9 +1280,6 @@ class NanoNemotronVLMultiModalProcessor(
 ):
     """MultiModalProcessor extended for video support"""
 
-    def _get_data_parser(self) -> MultiModalDataParser:
-        return MultiModalDataParser(video_needs_metadata=True)
-
     def _get_mm_fields_config(
         self,
         hf_inputs: BatchFeature,