[CI/Build][Bugfix] Fix Qwen2.5 tests in CPU CI via fallback silu_and_mul to...

[CI/Build][Bugfix] Fix Qwen2.5 tests in CPU CI via fallback silu_and_mul to torch native implementation (#22145)
Signed-off-by: jiang1.li <jiang1.li@intel.com>

vllm/model_executor/layers/activation.py

@@ -65,11 +65,13 @@ class SiluAndMul(CustomOp):
 
     def __init__(self):
         super().__init__()
-        if current_platform.is_cuda_alike() or current_platform.is_cpu():
+        if current_platform.is_cuda_alike():
             self.op = torch.ops._C.silu_and_mul
         elif current_platform.is_xpu():
             from vllm._ipex_ops import ipex_ops
             self.op = ipex_ops.silu_and_mul
+        elif current_platform.is_cpu():
+            self._forward_method = self.forward_native
 
     def forward_native(self, x: torch.Tensor) -> torch.Tensor:
         """PyTorch-native implementation equivalent to forward()."""