[Misc] Clean up more utils (#27567)

Signed-off-by: DarkLight1337 <tlleungac@connect.ust.hk>

vllm/platforms/__init__.py

@@ -60,7 +60,7 @@ def cuda_platform_plugin() -> str | None:
     is_cuda = False
     logger.debug("Checking if CUDA platform is available.")
     try:
-        from vllm.utils import import_pynvml
+        from vllm.utils.import_utils import import_pynvml
 
         pynvml = import_pynvml()
         pynvml.nvmlInit()