Add more options to the quantization model exporter (#18383)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/18383
Add command line options for different quantization schemes.
Reviewed By: amylittleyang
Differential Revision: D14476862
fbshipit-source-id: 37fbf5b4c1c550121eae313f5a71d703a0a87f0f
