target/arm: Clear SVE high bits for FMOV

target/arm: Clear SVE high bits for FMOV

Use write_fp_dreg and clear_vec_high to zero the bits
that need zeroing for these cases.

Cc: qemu-stable@nongnu.org
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20180502221552.3873-5-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
(cherry picked from commit 9a9f1f59521f46e8ff4527d9a2b52f83577e2aa3)
Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>