riscv: Fix the RVV build Use the correct RVV intrinsic, i.e., `__riscv_vaaddu_vv_u8m1` instead of `__riscv_vaaddu_wx_u8m1`. Reviewed-by: Cosmin Truta <ctruta@gmail.com> Signed-off-by: Cosmin Truta <ctruta@gmail.com>