[refactor] refactor deepseek-related files (#2849)

### What this PR does / why we need it?
This PR deletes ~2K lines of code about deepseek modeling. It falls back
CustomDeepseekV2 modules to original vllm implementations and adapts
some modifications in vllm about deepseek and moe.
### Does this PR introduce _any_ user-facing change?
No.
### How was this patch tested?
E2E  vllm serving with torchair graph mode and eager mode.

- vLLM version: v0.10.2
- vLLM main:
759ef49b15

---------

Signed-off-by: linfeng-yuan <1102311262@qq.com>
Signed-off-by: Yizhou Liu <liu_yizhou@outlook.com>
Co-authored-by: yiz-liu <136800916+yiz-liu@users.noreply.github.com>
Co-authored-by: Yizhou Liu <liu_yizhou@outlook.com>

vllm_ascend/patch/worker/patch_common/__init__.py

@@ -18,3 +18,4 @@
 import vllm_ascend.patch.worker.patch_common.patch_distributed  # noqa
 import vllm_ascend.patch.worker.patch_common.patch_logits  # noqa
 import vllm_ascend.patch.worker.patch_common.patch_minicpm  # noqa
+import vllm_ascend.patch.worker.patch_common.patch_shared_fused_moe  # noqa

vllm_ascend/patch/worker/patch_common/patch_shared_fused_moe.py

@@ -0,0 +1,21 @@
+# Copyright (c) 2025 Huawei Technologies Co., Ltd. All Rights Reserved.
+# Copyright 2023 The vLLM team.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+from vllm.model_executor.models import deepseek_v2, llama4
+
+from vllm_ascend.ops.common_fused_moe import AscendSharedFusedMoE
+
+deepseek_v2.SharedFusedMoE = AscendSharedFusedMoE
+llama4.SharedFusedMoE = AscendSharedFusedMoE