[CPU] support LayerNorm with 3D shape (#15075)

Co-authored-by: Ma Mingfei <mingfei.ma@intel.com>

python/sglang/srt/layers/layernorm.py

@@ -421,8 +421,9 @@ class LayerNorm(MultiPlatformOp):
         x: torch.Tensor,
     ) -> torch.Tensor:
         if _is_cpu_amx_available:
+            bias_data = self.bias.data if self.use_bias else None
             return torch.ops.sgl_kernel.layernorm_cpu(
-                x, self.weight.data, self.variance_epsilon
+                x, self.weight.data, bias_data, self.variance_epsilon
             )
         else:
             return self.forward_native(x)