Bump xa minor to signal that the underlying mesa version is suitable for dri3.

This is a bit ugly since it doesn't relate to a specific xa interface change.
Recently there has been a number of fixes in mesa that helps enabling dri3
without any significant regressions in automated testing and common desktop
usage latency. However, the xf86-video-vmware driver has no other way to tell
but inspecting the xa version.

Signed-off-by: Thomas Hellstrom <thellstrom@vmware.com>
Reviewed-by: Brian Paul <brianp@vmware.com>