egl: make it clear which platform x11 backend is being used (dri2 or 3)

Signed-off-by: Martin Peres <martin.peres@linux.intel.com>
Reviewed-by: Boyan Ding <boyan.j.ding@gmail.com>
Reviewed-by: Kristian Høgsberg <krh@bitplanet.net>
Reviewed-by: Emil Velikov <emil.velikov@collabora.co.uk>
3 files changed