The controller plugins can get the screen resolution directly from
weston output. Therefore, this API is not required.
Signed-off-by: Emre Ucan <eucan@de.adit-jv.com>
Reviewed-by: Pekka Paalanen <pekka.paalanen@collabora.co.uk>
Acked-by: Wataru Natsume <wnatsume@jp.adit-jv.com>