Use uint16_t instead of char16_t (C++11 compliance)

Change-Id: Iaf99c9b38e367e94642883fe4c05ab0bdce46b7e
Signed-off-by: Bernhard Rosenkränzer <Bernhard.Rosenkranzer@linaro.org>
Signed-off-by: Chet Kener <Cl3Kener@gmail.com>