[1/N][Attention] Restructure attention: move files (#31916)

Signed-off-by: Matthew Bonanni <mbonanni@redhat.com>

vllm/model_executor/models/step3_vl.py

@@ -15,11 +15,11 @@ from torchvision import transforms
 from torchvision.transforms.functional import InterpolationMode
 from transformers import BatchFeature, PretrainedConfig, TensorType
 
-from vllm.attention.layers.mm_encoder_attention import MMEncoderAttention
 from vllm.config import VllmConfig
 from vllm.config.multimodal import BaseDummyOptions
 from vllm.distributed import get_tensor_model_parallel_world_size
 from vllm.model_executor.layers.activation import get_act_fn
+from vllm.model_executor.layers.attention.mm_encoder_attention import MMEncoderAttention
 from vllm.model_executor.layers.conv import Conv2dLayer
 from vllm.model_executor.layers.linear import (
     ColumnParallelLinear,