【feat】switch for fusion ops gmmswigluquant (#5992)

### What this PR does / why we need it?

Set a additional config parameter to control whether the gmmswigluequant
fuseion operator is enabled; it is enabled by True. / When enabled with
a small number of GPUs, the gmmswigluquant fused operator can cause some
performance degradation.

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

### How was this patch tested?

- vLLM version: v0.13.0
- vLLM main:
2c24bc6996

#### Perf

test model: GLM 4.6(w8a8)
- single A3 node(ep16, tp16),  async-scheduling, mtp, FULL_DECODE_ONLY
- bs=1, input_lens=32000, ouput_lens=1024

Without this PR: TPOT 32.22.ms
With this PR: TPOT 30.23ms

---------

Signed-off-by: zjks98 <zhangjiakang4@huawei.com>
Co-authored-by: zjks98 <zhangjiakang4@huawei.com>

vllm_ascend/ascend_config.py

@@ -37,6 +37,9 @@ class AscendConfig:
         ascend_compilation_config = additional_config.get("ascend_compilation_config", {})
         self.ascend_compilation_config = AscendCompilationConfig(**ascend_compilation_config)
 
+        ascend_fusion_config = additional_config.get("ascend_fusion_config", {})
+        self.ascend_fusion_config = AscendFusionConfig(**ascend_fusion_config)
+
         finegrained_tp_config = additional_config.get("finegrained_tp_config", {})
         self.finegrained_tp_config = FinegrainedTPConfig(finegrained_tp_config, vllm_config)
 
@@ -190,6 +193,24 @@ class AscendCompilationConfig:
         self.fuse_allreduce_rms = fuse_allreduce_rms
 
 
+class AscendFusionConfig:
+    """
+    Configuration for controlling whether to use a fused operator gmmswigluquant.
+    """
+
+    def __init__(self, fusion_ops_gmmswigluquant: bool = True, **kwargs):
+        """
+        Initialize the configuration.
+
+        Args:
+            fusion_ops_gmmswigluquant (bool): Whether to use a fused operator gmmswigluquant.
+                When set to True, the system will use a fused operator gmmswigluquant.
+                Default: True
+            **kwargs: Additional optional parameters for forward compatibility and configuration extension.
+        """
+        self.fusion_ops_gmmswigluquant = fusion_ops_gmmswigluquant
+
+
 class XliteGraphConfig:
     """
     Configuration Object for xlite_graph_config from additional_config