[3/N][refactor] refactoer quantization (#2504)

### What this PR does / why we need it?
Move torchair related qunatization section into torchair dir to make the
code clear. Next step we'll remove all torchair related code outside of
torchair quantization.

### Does this PR introduce _any_ user-facing change?
NO

### How was this patch tested?
vLLM version: main
vLLM main:
ab9f2cfd19


- vLLM version: v0.10.1.1
- vLLM main:
959783fb99

Signed-off-by: hust17yixuan <303660421@qq.com>

vllm_ascend/torchair/quantization/torchair_quantizer.py

@@ -0,0 +1,29 @@
+from vllm_ascend.quantization.quantizer import VLLMAscendQuantizer
+from vllm_ascend.torchair.quantization.torchair_w4a8_dynamic import (
+    TorchairAscendW4A8DynamicFusedMoEMethod,
+    TorchairAscendW4A8DynamicLinearMethod)
+from vllm_ascend.torchair.quantization.torchair_w8a8_dynamic import (
+    TorchairAscendW8A8DynamicFusedMoEMethod,
+    TorchairAscendW8A8DynamicLinearMethod)
+
+
+class TorchairW8A8DYNAMICQuantizer(VLLMAscendQuantizer):
+
+    @staticmethod
+    def build_linear_method():
+        return TorchairAscendW8A8DynamicLinearMethod()
+
+    @staticmethod
+    def build_moe_method():
+        return TorchairAscendW8A8DynamicFusedMoEMethod()
+
+
+class TorchairW4A8DYNAMICQuantizer(VLLMAscendQuantizer):
+
+    @staticmethod
+    def build_linear_method():
+        return TorchairAscendW4A8DynamicLinearMethod()
+
+    @staticmethod
+    def build_moe_method():
+        return TorchairAscendW4A8DynamicFusedMoEMethod()