[1/N] Reorganize multimodal processing code (#32327)

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

vllm/model_executor/models/gemma3_mm.py

@@ -21,7 +21,8 @@ from vllm.multimodal.inputs import (
     MultiModalKwargsItems,
 )
 from vllm.multimodal.parse import ImageProcessorItems, ImageSize, MultiModalDataItems
-from vllm.multimodal.processing import (
+from vllm.multimodal.processing import BaseDummyInputsBuilder
+from vllm.multimodal.processing.processor import (
     BaseMultiModalProcessor,
     BaseProcessingInfo,
     MultiModalPromptUpdates,
@@ -32,7 +33,6 @@ from vllm.multimodal.processing import (
     PromptUpdateDetails,
     replace_token_matches,
 )
-from vllm.multimodal.profiling import BaseDummyInputsBuilder
 from vllm.sequence import IntermediateTensors
 from vllm.utils.tensor_schema import TensorSchema, TensorShape