[llvm] [AArch64] Remove wrong processor feature (PR #151289)

[David Spickett via llvm-commits]

DavidSpickett wrote:

Ok, better, but why is the feature wrong?

If I do a downstream merge and see that this change made my benchmarks go one way or the other, that's what I'd be looking for in the commit message. Perhaps the intent was good you just want to implement it differently, perhaps you found it made zero difference and doesn't need to be there, whatever the reason is.

https://github.com/llvm/llvm-project/pull/151289