OMAPDSS: store managers in an array

Overlay managers are stored in a linked list. There's no need for this
list, as an array would do just as fine.

This patch changes the code to use an array for overlay managers.

Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>

include/video/omapdss.h

@@ -418,7 +418,6 @@ struct omap_overlay_manager_info {
 
 struct omap_overlay_manager {
 	struct kobject kobj;
-	struct list_head list;
 
 	/* static fields */
 	const char *name;