Fix dropout in TFMobileBert (#5150)

src/transformers/modeling_tf_mobilebert.py

@@ -370,7 +370,7 @@ class TFMobileBertOutput(tf.keras.layers.Layer):
 
         hidden_states = self.dense(hidden_states)
         if not self.use_bottleneck:
-            hidden_states = self.dropout(hidden_states)
+            hidden_states = self.dropout(hidden_states, training=training)
             hidden_states = self.LayerNorm(hidden_states + residual_tensor_1)
         else:
             hidden_states = self.LayerNorm(hidden_states + residual_tensor_1)