Migrate prelu from CUDA_tensor_apply2 to TensorIterator (#34003)
Summary: Pull Request resolved: https://github.com/pytorch/pytorch/pull/34003
Test Plan: Imported from OSS
Differential Revision: D20196994
Pulled By: VitalyFedyunin
fbshipit-source-id: 1749a968b1ec6636e08c11c93de43b5599e7cf4b