[platform] add device_control env var (#12009)

Signed-off-by: youkaichao <youkaichao@gmail.com>

vllm/platforms/rocm.py

@@ -65,6 +65,8 @@ class RocmPlatform(Platform):
     device_type: str = "cuda"
     dispatch_key: str = "CUDA"
     ray_device_key: str = "GPU"
+    # rocm shares the same device control env var as CUDA
+    device_control_env_var: str = "CUDA_VISIBLE_DEVICES"
 
     supported_quantization: list[str] = [
         "awq", "gptq", "fp8", "compressed_tensors", "compressed-tensors",