Revert "AMDGPU/NFC: Cleanup subtarget predicates"

It breaks one of our downstream merges, so revert it
temporarily while investigating failures downstream


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@354700 91177308-0d34-0410-b5e6-96231b3b80d8
14 files changed