meson: drop the xcb-xrandr version requirement

autotools doesn't have any requirement. This fixes meson on Ubuntu 16.04.

Cc: 18.3 19.0 <mesa-stable@lists.freedesktop.org>
Reviewed-by: Erik Faye-Lund <erik.faye-lund@collabora.com>
(cherry picked from commit 1e85cfb9)