target/arm: Add isar_feature_aa32_vfp_simd

target/arm: Add isar_feature_aa32_vfp_simd

Use this in the places that were checking ARM_FEATURE_VFP, and
are obviously testing for the existance of the register set
as opposed to testing for some particular instruction extension.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Message-id: 20200224222232.13807-2-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>