[llvm] [AArch64] Remove TargetParser CPU/Arch feature tests (PR #104587)

[Sam Elliott via llvm-commits]

lenary wrote:

I think this broke a buildbot that's using `-Werror` - https://lab.llvm.org/buildbot/#/builders/145/builds/1332 - there's an internal function that's unused now?

https://github.com/llvm/llvm-project/pull/104587