[llvm] [RISCV] Don't promote f16 FNEG/FABS with Zfhmin/Zhinxmin. (PR #106474)

[Matt Arsenault via llvm-commits]

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

Also note that FCOPYSIGN has the same issue 

https://github.com/llvm/llvm-project/pull/106474