Tizen: Use QT_TIZEN_EMULATOR macro

Instead of deprecated Q_OS_LINUX_TIZEN_SIMULATOR.

Change-Id: I9de03126807ac3f32248594e63201234f7020b1e
Reviewed-by: Leon Anavi <leon@anavi.org>
Reviewed-by: Tomasz Olszak <olszak.tomasz@gmail.com>