Add silu fuser pass

[wjj19950828]

Create A Good Pull Request

下面的文字请保留在PR说明的最后面，并在提完PR后，根据实际情况勾选确认以下情况

Please check the follow step before merging this pull request

• [x] Python code style verification
• [x] Review all the code diff by yourself
• [ ] All models(TensorFLow/Caffe/ONNX/PyTorch) testing passed
• [x] Details about your pull request, releated issues

If this PR add new model support, please update model_zoo.md and add model to out test model zoos(@wjj19950828)

• [ ] New Model Supported
• [x] No New Model Supported

Do follow contributes

1、添加ONNX silu fuser pass 融合前： 融合后： 2、yolov5s模型op数：308下降到251