Fix autocast deprecation warning.

transformer_engine/pytorch/module/base.py

@@ -575,7 +575,7 @@ def set_activation_dtype(self, inp: torch.Tensor) -> None:
         """Get activation data type for AMP."""
         # Native AMP (`torch.autocast`) gets highest priority
         if torch.is_autocast_enabled():
-            self.activation_dtype = torch.get_autocast_gpu_dtype()
+            self.activation_dtype = torch.get_autocast_dtype('cuda')
             return
 
         # All checks after this have already been performed once, thus skip