!12406 ml_2012_ocr_cn fp16 back to gate

From: @zhaozhenlong
Reviewed-by: @zhanghaibo5,@hangangqiang
Signed-off-by: @zhanghaibo5

mindspore/lite/test/models_onnx_fp16.cfg

@@ -26,7 +26,7 @@ crnn_lite_lstm_v2.onnx;32,32,32,1 0.3
 psenet_lite_mbv2.onnx;1,32,32,3 0.6
 super-resolution-10.onnx;1,224,224,1 4.5
 tinyyolov2-8.onnx;1,416,416,3 5.5
-#ml_2012_ocr_cn.onnx -1
+ml_2012_ocr_cn.onnx -1
 #ml_2012_ocr_cn_noLSTM.onnx 1
 candy-9.onnx 5
 mosaic-9.onnx 4