drm: Use NativeDisplayType instead of Display

The latter does not exist if X11 headers are not being used,
and they should definitely not be used for the DRM/KMS platform
plug-in.

Author: aperezdc

platform/drm/cog-platform-drm.c

@@ -669,7 +669,7 @@ init_egl (void)
     if (s_eglGetPlatformDisplay)
         egl_data.display = s_eglGetPlatformDisplay (EGL_PLATFORM_GBM_KHR, gbm_data.device, NULL);
     else
-        egl_data.display = eglGetDisplay((Display *) gbm_data.device);
+        egl_data.display = eglGetDisplay((NativeDisplayType *) gbm_data.device);
 
     if (!egl_data.display) {
         clear_egl ();