[Fix doc example] TFLayoutLMForTokenClassification: missing import tf (#15268)

* fix import

* remove import torch
Co-authored-by: ydshieh <ydshieh@users.noreply.github.com>

src/transformers/models/layoutlm/modeling_tf_layoutlm.py

@@ -1382,8 +1382,8 @@ class TFLayoutLMForTokenClassification(TFLayoutLMPreTrainedModel, TFTokenClassif
         Examples:
 
         ```python
+        >>> import tensorflow as tf
         >>> from transformers import LayoutLMTokenizer, TFLayoutLMForTokenClassification
-        >>> import torch
 
         >>> tokenizer = LayoutLMTokenizer.from_pretrained("microsoft/layoutlm-base-uncased")
         >>> model = TFLayoutLMForTokenClassification.from_pretrained("microsoft/layoutlm-base-uncased")