OMAPDSS: add missing export for omap_dss_get_output()

omap_dss_get_output() is a public function, but was missing
EXPORT_SYMBOL().

Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
Reviewed-by: Archit Taneja <archit@ti.com>

drivers/video/omap2/dss/output.c

@@ -113,6 +113,7 @@ struct omap_dss_output *omap_dss_get_output(enum omap_dss_output_id id)
 
 	return NULL;
 }
+EXPORT_SYMBOL(omap_dss_get_output);
 
 static const struct dss_mgr_ops *dss_mgr_ops;