Centralize soc_to_chipset map (#6033)

Summary:
Pull Request resolved: https://github.com/pytorch/executorch/pull/6033

We have multiple copy of the maps in the codebase and it's error prone. Provide a util function for the map so we can get the map from the same function

Reviewed By: kirklandsign

Differential Revision: D64080089

fbshipit-source-id: eb3fff31808a20e666f4a3946c550c1e11b1d961