add clear for tensor

* [LITE][OPENCL] Add depthwise_conv_3x3 opencl kernel

* [LITE][OPENCL] Add depthwise_conv_3x3 opencl kernel. test=develop

* [LITE][OPENCL] Add Pool opencl kernel. test=develop

[LITE][OPENCL] Fix layout, target pass for OpenCL, add macro of CONVERT_TYPE_TO and READ/WRITE image, memory reuse in ResetLazyImage2D (#2170)

* add macro of CONVERT_TYPE_TO and READ/WRITE image. test=develop

* add data type control. test=develop

* fix io op as general layout and precision. test=develop

* Fix memory reuse strategy for opencl image2d. test=develop

* remove std::array, std::map in about opencl backend. test=develop

* [LITE][OPENCL] support image2d. test=develop

* add context changed with consider image*. test=develop

* add layout, relu image kernels. test=develop

* replace image_data with data, mutable_image_data with mutable_data, test=develop

* comment unused var. test=develop

* remove unused var. test=develop

* paddle lite cuda init
can run model with leaky_relu

* add the missing file.
test=develop