package/mesa3d: vulkan with x11 needs dri3

Vulcan with X11 needs DRI3, which in turn requires xlib-libxshmfence.

Fixes:
    http://autobuild.buildroot.org/results/356/35653fc6f57dc169a8aae6baedb1acd1049b50ec/



Signed-off-by: "Yann E. MORIN" <yann.morin.1998@free.fr>
Cc: Bernd Kuhls <bernd.kuhls@t-online.de>
Cc: Romain Naour <romain.naour@gmail.com>
Cc: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>