OMAPDSS: DISPC: add dispc_mgr_get_sync_lost_irq()

Add function that returns the sync lost irq mask for the given channel.

Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
diff --git a/drivers/video/omap2/dss/dss.h b/drivers/video/omap2/dss/dss.h
index 19d5663..bf9b7a4 100644
--- a/drivers/video/omap2/dss/dss.h
+++ b/drivers/video/omap2/dss/dss.h
@@ -434,6 +434,7 @@
 
 u32 dispc_mgr_get_vsync_irq(enum omap_channel channel);
 u32 dispc_mgr_get_framedone_irq(enum omap_channel channel);
+u32 dispc_mgr_get_sync_lost_irq(enum omap_channel channel);
 bool dispc_mgr_go_busy(enum omap_channel channel);
 void dispc_mgr_go(enum omap_channel channel);
 bool dispc_mgr_is_enabled(enum omap_channel channel);