fix autotune option

Author: fsx950223

efficientnetv2/datasets.py

@@ -549,7 +549,7 @@ def _input_fn(self, batch_size, current_host, num_hosts):
     ds = ds.prefetch(1)
 
     options = tf.data.Options()
-    options.experimental_optimization.autotune = True
+    options.autotune.enabled = True
     return ds.with_options(options)