OMAPDSS: store overlays in a list for each manager

Current way of handling overlay-manager links is a bit strange: each
manager has a static array, containing pointers to all the overlays
(even those used by other managers). The overlays contain a pointer to
the manager being used.

This patch makes the system a bit saner: each manager has a linked list
of overlays, and only the overlays linked to that manager are in the
list.

Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
diff --git a/include/video/omapdss.h b/include/video/omapdss.h
index fd5a96c..eaeca89 100644
--- a/include/video/omapdss.h
+++ b/include/video/omapdss.h
@@ -423,8 +423,7 @@
 	const char *name;
 	enum omap_channel id;
 	enum omap_overlay_manager_caps caps;
-	int num_overlays;
-	struct omap_overlay **overlays;
+	struct list_head overlays;
 	enum omap_display_type supported_displays;
 
 	/* dynamic fields */