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/dispc.c b/drivers/video/omap2/dss/dispc.c
index bfa0d1d..c50270e 100644
--- a/drivers/video/omap2/dss/dispc.c
+++ b/drivers/video/omap2/dss/dispc.c
@@ -542,6 +542,11 @@
 	return mgr_desc[channel].framedone_irq;
 }
 
+u32 dispc_mgr_get_sync_lost_irq(enum omap_channel channel)
+{
+	return mgr_desc[channel].sync_lost_irq;
+}
+
 u32 dispc_wb_get_framedone_irq(void)
 {
 	return DISPC_IRQ_FRAMEDONEWB;