OMAPDSS: fix missing EXPORT_SYMBOL()s

Functions dispc_ovl_set_fifo_threshold and
dispc_ovl_compute_fifo_thresholds need to be exported. Add the
EXPORT_SYMBOLs.
Signed-off-by: NTomi Valkeinen <tomi.valkeinen@ti.com>

drivers/video/omap2/dss/dispc.c

@@ -1201,6 +1201,7 @@ void dispc_ovl_set_fifo_threshold(enum omap_plane plane, u32 low, u32 high)
 			FLD_VAL(high, hi_start, hi_end) |
 			FLD_VAL(low, lo_start, lo_end));
 }
+EXPORT_SYMBOL(dispc_ovl_set_fifo_threshold);
 
 void dispc_enable_fifomerge(bool enable)
 {
@@ -1259,6 +1260,7 @@ void dispc_ovl_compute_fifo_thresholds(enum omap_plane plane,
 		*fifo_high = total_fifo_size - buf_unit;
 	}
 }
+EXPORT_SYMBOL(dispc_ovl_compute_fifo_thresholds);
 
 static void dispc_ovl_set_fir(enum omap_plane plane,
 				int hinc, int vinc,