[pyper][emb][quantization] Support emb trained in FP16 (#60736)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/60736
Add support of embedding with input data type as float16, utilize new kernel functions added in fbgemm https://github.com/pytorch/FBGEMM/pull/616
Test Plan: `buck test caffe2/test/:quantization -- test_embedding_bag`
Reviewed By: supriyar
Differential Revision: D29392320
fbshipit-source-id: 0a120b3a58b6cf1d84961831097e9581ffd2b591
