Revert D32404517: [quant][embedding qat] Support Embedding QAT via FX API
Test Plan: revert-hammer
Differential Revision:
D32404517 (https://github.com/pytorch/pytorch/commit/abda069ce203bbe9b655a939a58a7fedca86af80)
Original commit changeset: 0484df8c826b
fbshipit-source-id: 4e7d62b9ccdb84eb4d184cd0b3c9506013fd8336
