[CustomOp] Register AscendSharedFusedMoE custom op (#2980)

### What this PR does / why we need it?
Register `AscendSharedFusedMoE` custom op.

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

No.

### How was this patch tested?

`DeepSeek-V2-Lite` is a MoE model with shared experts.

Test:

```bash
vllm serve /root/.cache/modelscope/hub/models/deepseek-ai/DeepSeek-V2-Lite \
--trust-remote-code \
--enforce-eager \
--no-enable-prefix-caching \
--gpu-memory-utilization 0.95

curl -X POST http://localhost:8000/v1/chat/completions \
    -H "Content-Type: application/json" \
    -d '{
        "model": "/root/.cache/modelscope/hub/models/deepseek-ai/DeepSeek-V2-Lite",
        "messages": [
            {"role": "user", "content": "介绍一下联通公司？"}
        ],
        "stream": false,
        "max_tokens": 100
    }'
```

Output:

```bash
中国联合网络通信集团有限公司（简称“中国联通”）于2009年1月6日在原中国网通和原中国联通的基础上合并组建而成，在国内31个省（自治区、直辖市）和境外多个国家和地区设有分支机构，是中国唯一一家在纽约、香港、上海三地同时上市的电信运营企业，连续多年入选“世界500强企业”。\n\n中国联通主要经营固定通信业务，移动通信业务，国内
```


- vLLM version: v0.10.2
- vLLM main:
486c5599e3

---------

Signed-off-by: Shanshan Shen <87969357+shen-shanshan@users.noreply.github.com>
Signed-off-by: shen-shanshan <467638484@qq.com>

vllm_ascend/utils.py

@@ -498,7 +498,8 @@ def register_ascend_customop(vllm_config: Optional[VllmConfig] = None):
 
     from vllm_ascend.models.layers.mla import AscendMultiHeadLatentAttention
     from vllm_ascend.ops.activation import AscendQuickGELU, AscendSiluAndMul
-    from vllm_ascend.ops.common_fused_moe import AscendFusedMoE
+    from vllm_ascend.ops.common_fused_moe import (AscendFusedMoE,
+                                                  AscendSharedFusedMoE)
     from vllm_ascend.ops.layernorm import AscendQuantRMSNorm, AscendRMSNorm
     from vllm_ascend.ops.linear import (AscendColumnParallelLinear,
                                         AscendMergedColumnParallelLinear,
@@ -525,6 +526,7 @@ def register_ascend_customop(vllm_config: Optional[VllmConfig] = None):
         "LogitsProcessor": AscendLogitsProcessor,
         "RMSNorm": AscendRMSNorm,
         "FusedMoE": AscendFusedMoE,
+        "SharedFusedMoE": AscendSharedFusedMoE,
         "MultiHeadLatentAttention": AscendMultiHeadLatentAttention,
     }