[caffe2] Replace embedding conversion ops with fbgemm functions (#44843)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/44843
Replace perfkernels calls with fbgemm kernels to avoid code duplication
ghstack-source-id: 112496292
Test Plan: CI
Reviewed By: radkris-git
Differential Revision: D23675519
fbshipit-source-id: 05c285a9eeb9ea109a04a78cb442a24ee40a4aec
