* add sgd op, test=develop

* test=develop

* add backend

* add kernel

* add grad kernel

* add mean op, test=develop

* split forward and backward, test=develop

* add lookup_dequant_op

* enhance gather, lookup_table arm kernel uts

* enhance beam_search, beam_search_decoder, increment rigster

* fix

* fix format. test=develop

* fix format, test=develop

* fix resize error

* fix format. test=develop

* fix format, test=develop

* fix format

* note log(4) << x_image. test=develop

* note x_image printf. test=develop

* fix: fix nlp ops input and output type
* fix: add elementwise x_dims>y_dims case

* Fix act bug for opencl kernel. test=develop

* add print ActToStr. test=develop

* remove print code. test=develop

* fix leakyrelu and tanh compute error, test=develop

* delete extra file, test=develop

* reset act

* fix conflict and readme, test=develop

* fix ios run error, 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

* add sequence_conv op and arm kernel

* add test, test=develop

* test=develop

* test=develop

* test=develop

* test=develop

* test=develop

* test=develop

* test=develop

* test=develop

* test=develop

* test=develop

* test=develop

* test=develop

* test=develop

* test=develop

* modify code style. test=develop

* fix ut, test=develop

* delete unused code, test=develop

* feat: add lstm op && kernel
      test=develop

* Support lac model, fix bug for argmax lod_reset, test=develop

fix: move quant op to basic

add multiclass_nms2 kernel, test=develop

* fix compile. test=develop

add cv docs, test=document_fix

test=develop

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

* Optimize the InferShape of several operators.
test=develop

* Remove the new function, resize and CheckPositive in DDim.
test=develop

* Fix a bug in fc_op's InferShape.
test=develop

1. add conv_5x5s2_dw to support any padding
2. add 1x1s2pooling impl
3. fix conv dw 3x3 s1p01 bug

- enhance interp InferShape

* support conv_transpose output_size attr test=develop

* Remove GEMM padding in fc_compute.
test=develop

* Write a common ParallelFor function to run the for loop in parallel.

* Add the codes of padding GEMM back in fc.

* Refine the code of fc when padding_weight is false to avoid the definition of temporary Tensor.

* Refine the unit test of fc and add testing case of padding and parallel.
test=develop

* Enable more test cases in common fc unittest, including padding and parallel for x86 target.

* Remove the fc test under kernels/x86.
test=develop

* Disable relu in test of fc for non-x86 target.
test=develop

* Change the eps of arm.
test=develop

* Support multiple types for XPU and NPU op bridges

* Add lookup_table, gather, slice, stack and scale op bridges for supporting BERT

* Fix the definition of lookup_table kernel for X86