[Perf]Enable npu_moe_gating_top_k_softmax on quantized scenarios (#2633)

### What this PR does / why we need it?
This PR enables `npu_moe_gating_top_k_softmax` when running quantized
MoE (such as W8A8). This op in fact makes no distinction between
quantized and non-quantized scenarios. Introducing this op reduces 3~4ms
for TPOT.

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

No.

### How was this patch tested?


- vLLM version: v0.10.1.1
- vLLM main:
ce30dca5c4

Signed-off-by: Angazenn <supperccell@163.com>

vllm_ascend/ops/fused_moe.py

@@ -173,8 +173,7 @@ class AscendUnquantizedFusedMoEMethod(UnquantizedFusedMoEMethod):
             custom_routing_function=custom_routing_function,
             scoring_func=scoring_func,
             e_score_correction_bias=e_score_correction_bias,
-            global_num_experts=global_num_experts,
-            is_unquantized=True)
+            global_num_experts=global_num_experts)
 
         topk_weights = topk_weights.to(x.dtype)
         # this is a naive implementation for experts load balance so as