packaging: disable XDG-Shell for Tizen

Current implementation only worked with patched Weston 1.4 on Tizen,
and Ozone-Wayland disabled 1.5 support upstream anyway, so disable
it to avoid crashes when Tizen switches to Weston 1.5.

BUG=XWALK-1907

Signed-off-by: Manuel Bachmann <manuel.bachmann@open.eurogiciel.org>
Merge pull request #2064 from Tarnyko/master

packaging: disable XDG-Shell for Tizen