Update for Zvkb extension.

Update for Zvkb extension.

https://github.com/riscv/riscv-crypto/blob/c8ddeb7e64a3444dda0438316af1238aeed72041/doc/vector/riscv-crypto-vector-zvkb.adoc
Create `RISCV_HAS_ZVKB()` macro.
Use zvkb for SM4 instead of zvbb.
Use zvkb for ghash instead of zvbb.
We could just use the zvbb's subset `zvkb` for flexibility.

Signed-off-by: Jerry Shih <jerry.shih@sifive.com>
Signed-off-by: Phoebe Chen <phoebe.chen@sifive.com>
Reviewed-by: Tomas Mraz <tomas@openssl.org>
Reviewed-by: Paul Dale <pauli@openssl.org>
Reviewed-by: Hugo Landau <hlandau@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/21923)