Patch *ForCausalLM model (#9092)

templates/adding_a_new_model/cookiecutter-template-{{cookiecutter.modelname}}/modeling_tf_{{cookiecutter.lowercase_modelname}}.py

@@ -872,6 +872,12 @@ class TF{{cookiecutter.camelcase_modelname}}ForCausalLM(TF{{cookiecutter.camelca
     def get_output_embeddings(self):
         return self.{{cookiecutter.lowercase_modelname}}.embeddings
 
+    def get_output_layer_with_bias(self):
+        return self.mlm.predictions
+
+    def get_prefix_bias_name(self):
+        return self.name + "/" + self.mlm.name + "/" + self.mlm.predictions.name
+
     @add_code_sample_docstrings(
         tokenizer_class=_TOKENIZER_FOR_DOC,
         checkpoint="{{cookiecutter.checkpoint_identifier}}",