* rename pten dir to phi

* rename namespace to phi

* rename infrt pten dir to phi

* resolve conflict

* rename pten to phi in cmake

* revert all infrt change

* change needed files

* fix infrt failed

* fix inference failed

* add more op int16 support

* fix xpu ci

* clean useless header in pten core

* fix compiled failed

* fix cmake target

* fix typo

* resolve conflict

[Pten]Refactor elementwise_add grad / double grad / triple grad Kernel and move them to pten (#39048)

* refactor elementwise add grad

* fix compile bugs

* fix unit test bugs

* fix file conflicts

* fix bugs when buildPtenContext