xwayland.weston-start: adaption of X11-unix folder

changed permission of X11-unix to 775
changed owner of X11-unix to root:video

Signed-off-by: ssuesens <sebastian.suesens@baslerweb.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>