* Convert split, pad and pad3d kernels

* Convert slice+grad oneDNN fluid kernels to PHI

* change out->mutable_data to dev_ctx.Alloc

* gaussian random

* mkldnn to onednn renaming

* fix merge conflicts

* remove fluid code

* onednn renaming

* Move classes from mkldnn_reuse.h to onednn_reuse.h

* Migrate pool+grad, clip+grad and cast oneDNN kernels to PHI

* Refactor grad kernels into separate files

* Fix CI failures

* Fix Codestyle

* Implement reviewer suggestions

* Add new lines after includes for readability
Co-authored-by: NSilv3S <slawomir.siwek@intel.com>

* gaussian random

* mkldnn to onednn renaming

* fix merge conflicts

* remove fluid code

* onednn renaming

* Move classes from mkldnn_reuse.h to onednn_reuse.h

* Move more functions from mkldnn_helper.h to onednn_helpper.h

* Change MKLDNN to OneDNN in VLOG message
Co-authored-by: NSilv3S <slawomir.siwek@intel.com>

* gaussian random

* mkldnn to onednn renaming

* fix merge conflicts

* remove fluid code

* onednn renaming

* change header path

* change fluid import to phi

* compile into one static library

* fix xpu compile

* fix xpu compile

* fix inference compile

* fix inference compile

* add custom test

* revert one file

* adapt mkldnn kernel in PHI

* fix ci compile bugs

* fix compile bugs

* fix compile bugs

* fix compile bugs

* fix compile bugs

* delete comment

* fix compile bugs in windows-inference

* delete code for converage

* modify code by review

* modify code by review

* add todo

* fix compile bugs

* fix compile bugs

* fix compile bugs

* fix unittest bugsx