[llvm] [AArch64] SME definitions for C1-Ultra scheduling model (PR #194850)

[Nashe Mncube via llvm-commits]

https://github.com/nasherm commented:

> I was wondering if some sort of warning for llvm-mca might be useful for users.

I have added a warning to LLVM-MCA. Also tried to respond to all comments

https://github.com/llvm/llvm-project/pull/194850