[quant] Refactoring the mappings files (#44847)
Summary: Pull Request resolved: https://github.com/pytorch/pytorch/pull/44847
Test Plan: Imported from OSS
Reviewed By: jerryzh168
Differential Revision: D23747007
Pulled By: z-a-f
fbshipit-source-id: 7d8fcc84a77454cc1479e5158f5a62eda5824a87
