* add trt LT version helper

* remove deprecated nvinfer1::DimsCHW and replace it to nvinfer1::Dims3

* remove deprecated nvinfer1::DimsNCHW and replace it to nvinfer1::Dims4

* update deserialize engine

* update to createNetworkV2

* update to createNetworkV2

* update buildWithConfig and remove redundent config settings

* replace createNetwork to createNetworkV2

* fix int8

* addMatrixMultiply

* remove unnecessary const cast

* IBuilder->setInt8Calibrator() is deprecated

* auto enable fp16 when using int8

* remove the redundant line

* Initialize the elementwise plugin.

* Implement the basic CUDA kernel of elementwise plugin.
test=develop