[Platform] Move async output check to platform (#10768)

Signed-off-by: wangxiyuan <wangxiyuan1007@gmail.com>

vllm/platforms/xpu.py

@@ -1,4 +1,4 @@
-from typing import TYPE_CHECKING
+from typing import TYPE_CHECKING, Optional
 
 import torch
 
@@ -41,6 +41,10 @@ class XPUPlatform(Platform):
         device_props = torch.xpu.get_device_properties(device_id)
         return device_props.total_memory
 
+    @classmethod
+    def is_async_output_supported(cls, enforce_eager: Optional[bool]) -> bool:
+        return True
+
     @staticmethod
     def inference_mode():
         return torch.no_grad()