[clang] [llvm] [llvm][RISCV] Make zvknhb imply zvknha (PR #142896)

[Brandon Wu via llvm-commits]

4vtomat wrote:

> @4vtomat you did the opposite of this in [65dc96c](https://github.com/llvm/llvm-project/commit/65dc96c2cfa480b070c7913ac5e313c98ca96520). What changed now?
> 
> It was explicitly stated by one of the crypto authors here that Zvknhb does not imply Zvknha [riscv/riscv-crypto#364 (comment)](https://github.com/riscv/riscv-crypto/issues/364#issuecomment-1726782096)

Oh, I don't even remember I changed this before lol, thanks for the context!

https://github.com/llvm/llvm-project/pull/142896