clients: Fix build without Cairo/GLES2

If we're building with EGL support generally, but without Cairo/GLESv2,
building the clients fail, because window.c defines the EGL native
types, however platform.h also brings these in.

Signed-off-by: Daniel Stone <daniels@collabora.com>
Cc: Emil Velikov <emil.velikov@collabora.com>
Cc: Bryce Harrington <brycef@osg.samsung.com>
Reviewed-by: Pekka Paalanen <pekka.paalanen@collabora.co.uk>
Tested-by: Pekka Paalanen <pekka.paalanen@collabora.co.uk>
Reviewed-by: Emil Velikov <emil.velikov@collabora.com>
Acked-by: Bryce Harrington <bryce@osg.samsung.com>

clients/window.c

@@ -55,7 +55,7 @@
 #include <EGL/eglext.h>
 
 #include <cairo-gl.h>
-#else /* HAVE_CAIRO_EGL */
+#elif !defined(ENABLE_EGL) /* platform.h defines these if EGL is enabled */
 typedef void *EGLDisplay;
 typedef void *EGLConfig;
 typedef void *EGLContext;