package/weston: drop fbdev

fbdev raises the following build failure since bump to version 10.0.0 in
commit f67a6e9b and
https://gitlab.freedesktop.org/wayland/weston/-/commit/6338dbd5816689b2f08f48b359a972e16ff038d8:

../output-1/build/weston-10.0.0/meson.build:133:7: ERROR: Tried to access unknown option 'backend-fbdev'.

Drop fbdev to avoid this build failure as upstream is reluctant to
properly fix this issue by renaming the fbdev option in stable release:
https://gitlab.freedesktop.org/wayland/weston/-/merge_requests/791

Fixes:
 - http://autobuild.buildroot.org/results/e669a6237c19783c627169c819d7372e20daaf54



Signed-off-by: Fabrice Fontaine <fontaine.fabrice@gmail.com>
Signed-off-by: Arnout Vandecappelle (Essensium/Mind) <arnout@mind.be>