This commit updates the cpp_synchronization sample to enable `CONFIG_CPP_MAIN` since it defines its main() in a C++ source file. Signed-off-by: Stephanos Ioannidis <stephanos.ioannidis@nordicsemi.no>
CPP is a subsystem, so move this sample application where it belongs. Signed-off-by: Anas Nashif <anas.nashif@intel.com>