Building waylandpp for the target requires a wayland-scanner++ binary
built for the host.
Signed-off-by: Bernd Kuhls <bernd.kuhls@t-online.de>
[Thomas: use 'depends on BR2_PACKAGE_WAYLAND' instead of a select.]
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>