compositor: remove the weston_config field in weston_compositor

The config can now be retrieved with a new function defined in weston.h,
wet_get_config(weston_compositor*).

Signed-off-by: Giulio Camuffo <giuliocamuffo@gmail.com>
Reviewed-by: Pekka Paalanen <pekka.paalanen@collabora.co.uk>
Reviewed-by: Quentin Glidic <sardemff7+git@sardemff7.net>
diff --git a/src/weston.h b/src/weston.h
index f2bc1ac..ea42166 100644
--- a/src/weston.h
+++ b/src/weston.h
@@ -57,6 +57,9 @@
 void
 weston_watch_process(struct weston_process *process);
 
+struct weston_config *
+wet_get_config(struct weston_compositor *compositor);
+
 #ifdef  __cplusplus
 }
 #endif