[llvm] Revert "Add HexagonGlobalScheduler pass (#180803)" (PR #181418)

[Ankit Aggarwal via llvm-commits]

https://github.com/aankit-ca approved this pull request.

Previous patch https://github.com/llvm/llvm-project/pull/180803 is failing on a few lit tests.

https://github.com/llvm/llvm-project/pull/181418