Someone trying to compile cogl (ThijsNL on irc0 for the Rasberry Pi
stumbled into that one. GLXDrawable may not be defined in a pure EGL/X
environment.
Change it to Window, the type used for XConfigureEvent.window.
Reviewed-by: Neil Roberts <neil@linux.intel.com>
(cherry picked from commit f05d6923fff28b1d167a391d486e319743c49215)