dri/vmwgfx: Disable a couple of glx extensions also for Ubuntu unity / compiz

dri/vmwgfx: Disable a couple of glx extensions also for Ubuntu unity / compiz

It appears like the GLX_EXT_buffer_age extension also prevents Compiz /
Ubuntu Unity from performing partial buffer swaps when it otherwise
feels like doing so. So try to get them back again. We also disable
GLX_OML_sync_control since it appears it had a favourable impact on
gnome-shell.

Signed-off-by: Thomas Hellstrom <thellstrom@vmware.com>
Reviewed-by: Sinclair Yeh <syeh@vmware.com>