outputs wrongly

    1. disable conv activation pass by default
    2. set fc_fuser'param with_relu false while mlu fc kernel does not
    support relu
    3. change fc filter shape from 2 dim to 4 dim while input dim == 4
    4. add ToFile func in mlu tensor for debug convenience
    5. enable 4-dim input in elementwise_ops
    6. add transpose2d in utility.cc

target -> subgraph -> target -> precision -> layout

* Fix OpenCL kernel of exp, tanh,

* Fix layout pass for opencl backend,

* Add how to debug cl kernel. test=develop.

* fix some error when compiling with mlu-sdk1.2.5

This reverts commit 670fcc3c.

* [MLU] support resnet50 on MLU

* [MLU] support resnet50 on MLU

* Fix memory_resuse for opencl. test=develop

* remove useless code. test=develop

* [LITE][OPENCL] Support video-sr feature using OpenCL FP16 Image. test=develop

* optimize image2d_to_buffer_with_post255. test=develop

* add def debug in cl kernel. test=develop

* remove conv image code in conv buffer. test=develop

[LITE][OPENCL] support fp16 for cl_image_converter, layout, activation all OpenCL image kernel. test=develop (#2964)

* [LITE][OPENCL] support fp16 for cl_image_converter, layout, activation image kernel. test=develop

* add conv, depthwise and UT. test=develop

* add pool, conv, nearest_interp kernel. test=develop

* support fp16 for scale, reshape, concat, fc buffer opencl kernel. test=develop

* refactor for mul opencl buffer kernel. test=develop

* support fp16 for elementwise_mul opecl image kernel. test=develop

* support fp16 for elementwise_mul opencl image kernel. test=develop

* support fp16 for ele_add, fuse_ele_add_act opencl kernel. test=develop

* rename io_copy. test=develop

* mobilenetv1,v2 passed on 855. test=develop

* fix opt for opencl. test=develop

skip fusing quantized conv2d + relu6 for now

fix fpga lite_tensor compile bug
     add fake quantize_abs_max op
     test=develop

* fix con+relu6/leakyRelu fusion in Fp32, test=develop

* note m=397 in sgemv_int8 ut, test=develop

* fix ios build error. test=develop

* optimize quant_dequant_fuse_pass, test=develop

* update, test=develop

* update, test=develop

* fix bug for accessing the removed node, test=develop

* set the bias of int8 conv as float, test=develop

* support weight quantization, test=develop

* up, test=develop

* up, test=develop

* up, test=develop