Revert "Support more model outputs for BERT/ERNIE/RoBERTa (#2583)" (#2647)

This reverts commit dab5e26.

Author: guoshengCS

paddlenlp/transformers/__init__.py

@@ -120,11 +120,4 @@
 if is_faster_tokenizer_available():
     from .bert.faster_tokenizer import *
     from .ernie.faster_tokenizer import *
-    from .tinybert.faster_tokenizer import *
-
-# patches of paddle.nn.Transformer to get all hidden_states and attentions
-import paddle
-from .model_outputs import _transformer_encoder_layer_fwd, _transformer_encoder_fwd
-
-paddle.nn.TransformerEncoderLayer.forward = _transformer_encoder_layer_fwd
-paddle.nn.TransformerEncoder.forward = _transformer_encoder_fwd
+    from .tinybert.faster_tokenizer import *