[CPU] Fix issue: No module named 'fbgemm_gpu.experimental' (#3292)

fix fbgemm_gpu import issue

Author: shiyang-weng

torchao/utils.py

@@ -1153,7 +1153,10 @@ def is_package_at_least(package_name: str, min_version: str):
 def _is_fbgemm_gpu_genai_available():
     # TODO: use is_package_at_least("fbgemm_gpu", "1.2.0") when
     # https://github.com/pytorch/FBGEMM/issues/4198 is fixed
-    if importlib.util.find_spec("fbgemm_gpu") is None:
+    if (
+        importlib.util.find_spec("fbgemm_gpu") is None
+        or importlib.util.find_spec("fbgemm_gpu.experimental") is None
+    ):
         return False
 
     import fbgemm_gpu.experimental.gen_ai  # noqa: F401