Sync FindCUDA/select_computer_arch.cmake from upstream (#19392)
Summary:
1. Fixes auto detection for Turing cards.
2. Adds Turing Support
Pull Request resolved: https://github.com/pytorch/pytorch/pull/19392
Differential Revision: D14996142
Pulled By: soumith
fbshipit-source-id: 3cd45c58212cf3db96e5fa19b07d9f1b59a1666a
