This covers the encoding group:

  Advanced SIMD scalar three same FP16

As all the helpers are already there it is simply a case of calling the
existing helpers in the scalar context.
Signed-off-by: NAlex Bennée <alex.bennee@linaro.org>
Reviewed-by: NRichard Henderson <richard.henderson@linaro.org>
Message-id: 20180227143852.11175-31-alex.bennee@linaro.org
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>