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

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

vllm/model_executor/models/config.py

@@ -4,12 +4,12 @@ from copy import deepcopy
 from math import lcm
 from typing import TYPE_CHECKING
 
-from vllm.attention.backends.registry import AttentionBackendEnum
 from vllm.logger import init_logger
 from vllm.model_executor.models import ModelRegistry
 from vllm.platforms import current_platform
 from vllm.utils.math_utils import cdiv, round_up
 from vllm.utils.torch_utils import STR_DTYPE_TO_TORCH_DTYPE
+from vllm.v1.attention.backends.registry import AttentionBackendEnum
 from vllm.v1.kv_cache_interface import FullAttentionSpec, MambaSpec, MLAAttentionSpec
 
 if TYPE_CHECKING: