Migrate Lerp from CUDA_tensor_apply4 to TensorIterator (#33994)
Summary: Pull Request resolved: https://github.com/pytorch/pytorch/pull/33994
Test Plan: Imported from OSS
Differential Revision: D20196788
Pulled By: VitalyFedyunin
fbshipit-source-id: e5e281460e8cca7ea3911fe56549e1ab62d50e76
