[clang] [llvm] [mlir] [AArch64][SME] Improve codegen for aarch64.sme.cnts* when not in streaming mode (PR #154761)

[Benjamin Maxwell via llvm-commits]

https://github.com/MacDue approved this pull request.

Generally LGTM (mainly looking at the MLIR side), just a few final comments: 

https://github.com/llvm/llvm-project/pull/154761