wayland: don't use libdecor_frame_get_* functions when header doesn't have it and we're statically linking to the library. This fixes building SDL with -DSDL_WAYLAND_SHARED=OFF (cherry picked from commit 5b5b67df203e9f8391e7e53aa5de54abf14c482e) (cherry picked from commit e6f635ca172027f57542b715787ac5b50f3f6d33)