[llvm] [RISCV] Rename sf_vcix_state to sf.vcix_state. NFC (PR #107115)

[Kito Cheng via llvm-commits]

kito-cheng wrote:

Does [llvm/test/CodeGen/RISCV/rvv/copyprop.mir](https://github.com/llvm/llvm-project/pull/106995/files#diff-31b29607eda21ab0eaef2a385ae3b1fa04e36756a12ff513b689a634d069b8b8) need to update?

https://github.com/llvm/llvm-project/pull/107115