[clang] [llvm] [RISCV] Use BF16 in Xsfvfwmaccqqq intrinsics (PR #71140)

[Craig Topper via cfe-commits]

https://github.com/topperc requested changes to this pull request.

I believe we need to update `Sema::checkRVVTypeSupport` too

https://github.com/llvm/llvm-project/pull/71140