* add mul phi kernel

* remove mul op kernel

* remove original mul grad op

* fix cinn test

* fix dygraph test failed

* unify register macro

* rename declare macro

* fix infrt error

* 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

* clean useless header in pten core

* fix compiled failed

* fix cmake target

* fix typo

* resolve conflict

* Migrate bfloat16/float16/complex from platform into pten::common

* fix typo

* fix code style

* rename register marco

* fix error changing

* fix format error

* refactor matmul directory in pten

* fix merge conflict

* remove eigen and blas dir

* fix declare error