Move deepseek_v3 from deepseek_v2.py (#1793)

### What this PR does / why we need it?
Before patch, we can see
`vllm_ascend.models.deepseek_v2:CustomDeepseekV3ForCausalLM`, it seems
not friendly format.

```
WARNING 07-14 23:57:34 [registry.py:413] Model architecture DeepseekV2ForCausalLM is already registered, and will be overwritten by the new model class vllm_ascend.models.deepseek_v2:CustomDeepseekV2ForCausalLM.
WARNING 07-14 23:57:34 [registry.py:413] Model architecture DeepseekV3ForCausalLM is already registered, and will be overwritten by the new model class vllm_ascend.models.deepseek_v2:CustomDeepseekV3ForCausalLM.
WARNING 07-14 23:57:34 [registry.py:413] Model architecture Qwen3MoeForCausalLM is already registered, and will be overwritten by the new model class vllm_ascend.models.qwen3_moe:CustomQwen3MoeForCausalLM.
```


### Does this PR introduce _any_ user-facing change?

No.

### How was this patch tested?

Local Test.


- vLLM version: v0.9.2
- vLLM main:
vllm-project/vllm@bcdfb2a

Signed-off-by: xleoken <xleoken@163.com>

Author: xleoken

vllm_ascend/models/__init__.py

@@ -7,7 +7,7 @@ def register_model():
     from .deepseek_dbo import CustomDeepseekDBOForCausalLM  # noqa: F401
     from .deepseek_mtp import CustomDeepSeekMTP  # noqa: F401
     from .deepseek_v2 import CustomDeepseekV2ForCausalLM  # noqa: F401
-    from .deepseek_v2 import CustomDeepseekV3ForCausalLM  # noqa: F401
+    from .deepseek_v3 import CustomDeepseekV3ForCausalLM  # noqa: F401
     from .qwen2_5_vl import \
         AscendQwen2_5_VLForConditionalGeneration  # noqa: F401
     from .qwen2_vl import AscendQwen2VLForConditionalGeneration  # noqa: F401
@@ -47,7 +47,7 @@ def register_model():
 
         ModelRegistry.register_model(
             "DeepseekV3ForCausalLM",
-            "vllm_ascend.models.deepseek_v2:CustomDeepseekV3ForCausalLM")
+            "vllm_ascend.models.deepseek_v3:CustomDeepseekV3ForCausalLM")
 
     ModelRegistry.register_model(
         "Qwen3MoeForCausalLM",

vllm_ascend/models/deepseek_v2.py

@@ -979,7 +979,3 @@ def forward(
                                    attn_metadata, intermediate_tensors,
                                    inputs_embeds)
         return hidden_states
-
-
-class CustomDeepseekV3ForCausalLM(CustomDeepseekV2ForCausalLM):
-    pass

vllm_ascend/models/deepseek_v3.py

@@ -0,0 +1,27 @@
+# SPDX-License-Identifier: Apache-2.0
+# Copyright (c) 2025 Huawei Technologies Co., Ltd. All Rights Reserved.
+# Copyright 2023 The vLLM team.
+# Copyright 2023 DeepSeek-AI and the HuggingFace Inc. team. All rights reserved.
+#
+# This code is based on EleutherAI's GPT-NeoX library and the GPT-NeoX
+# and OPT implementations in this library. It has been modified from its
+# original forms to accommodate minor architectural differences compared
+# to GPT-NeoX and OPT used by the Meta AI team that trained the model.
+#
+# 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_ascend.models.deepseek_v2 import CustomDeepseekV2ForCausalLM
+
+
+class CustomDeepseekV3ForCausalLM(CustomDeepseekV2ForCausalLM):
+    pass