jhbuild: mesa: enable xa as it is required to build vmware driver
jhbuild: mesa: enable xa as it is required to build vmware driver

It exercises more code.

Signed-off-by: Gaetan Nadon <8a8cc541338200f67d4d0bcb65c78b6166649462@videotron.ca>

freedesktop-unofficial-mirror/xorg__util__modular,freedesktop-unofficial-mirror/xorg__util__modular,freedesktop-unofficial-mirror/xorg__util__modular