target/arm: Implement FMOV (immediate) for fp16

target/arm: Implement FMOV (immediate) for fp16

All the hard work is already done by vfp_expand_imm, we just need to
make sure we pick up the correct size.

Cc: qemu-stable@nongnu.org
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Tested-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20180512003217.9105-11-richard.henderson@linaro.org
[rth: Merge unallocated_encoding check with TCGMemOp conversion.]
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
(cherry picked from commit 6ba28ddb9be37bdb67e3e38007a53ccbdcd010df)
Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>