OMAPDSS: export dss_get_def_display_name()

Export dss_get_def_display_name() with the name of
omapdss_get_def_display_name() so that omapfb can use it after the next
patch which moves default display handling to omapfb.

Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
diff --git a/drivers/video/omap2/dss/dsi.c b/drivers/video/omap2/dss/dsi.c
index 7d0db2b..2ba505b 100644
--- a/drivers/video/omap2/dss/dsi.c
+++ b/drivers/video/omap2/dss/dsi.c
@@ -5100,7 +5100,7 @@
 {
 	struct omap_dss_board_info *pdata = pdev->dev.platform_data;
 	struct dsi_data *dsi = dsi_get_dsidrv_data(pdev);
-	const char *def_disp_name = dss_get_default_display_name();
+	const char *def_disp_name = omapdss_get_default_display_name();
 	struct omap_dss_device *def_dssdev;
 	int i;