remove unnecessary BoxedKernelWrapper specialization now that ops are all c10-full (#50963)
Summary: Pull Request resolved: https://github.com/pytorch/pytorch/pull/50963
Test Plan: Imported from OSS
Reviewed By: bhosmer
Differential Revision: D26026665
Pulled By: bdhirsh
fbshipit-source-id: ef6e515f7dae5052538789e5b75dc551b4ce3b11
