Optimize the MVE 1op-immediate insns (VORR, VBIC, VMOV) to
use TCG vector ops when possible.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20210913095440.13462-13-peter.maydell@linaro.org