* move label_smmoth XPU kernel to PHI,test=kunlun

* delete label_smooth_op_xpu.cc and modfied label_smooth_kernel.cc,test=kunlun

* delete add_label_smooth.cc,test=kunlun

* refactor the optional tensor

* remove optiona<MetaTensor> in InferMeta

* fix bug

* fix optional<vector<Tensor>>

* fix bug

* fix rmsprop

* fix amp of eager_gen

* polish code

* fix deleted code

* fix merge conflict

* polish code

* remove is_nullopt_

* fix merge conflict

* fix merge conflict

* [Phi] Migrate lable_smooth_op into Phi

* fix PT->PD