OMAP: DSS2: RFBI: add rfbi_bus_lock

Add similar bus lock to RFBI as is in DSI. The panel driver can use the
bus lock to mark that the RFBI bus is currently in use.

Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
diff --git a/include/video/omapdss.h b/include/video/omapdss.h
index e3c9e08..943c0e8 100644
--- a/include/video/omapdss.h
+++ b/include/video/omapdss.h
@@ -214,6 +214,8 @@
 int omap_rfbi_setup_te(enum omap_rfbi_te_mode mode,
 			     unsigned hs_pulse_time, unsigned vs_pulse_time,
 			     int hs_pol_inv, int vs_pol_inv, int extif_div);
+void rfbi_bus_lock(void);
+void rfbi_bus_unlock(void);
 
 /* DSI */
 void dsi_bus_lock(struct omap_dss_device *dssdev);