OMAPDSS: add omap_dss_find_output_by_node()

Add a support function to find a DSS output by given DT node. This is
used in later patches to link the panels to DSS outputs.

Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
diff --git a/drivers/video/omap2/dss/output.c b/drivers/video/omap2/dss/output.c
index 3274628..4d01001 100644
--- a/drivers/video/omap2/dss/output.c
+++ b/drivers/video/omap2/dss/output.c
@@ -128,6 +128,19 @@
 }
 EXPORT_SYMBOL(omap_dss_find_output);
 
+struct omap_dss_output *omap_dss_find_output_by_node(struct device_node *node)
+{
+	struct omap_dss_output *out;
+
+	list_for_each_entry(out, &output_list, list) {
+		if (out->pdev->dev.of_node == node)
+			return out;
+	}
+
+	return NULL;
+}
+EXPORT_SYMBOL(omap_dss_find_output_by_node);
+
 static const struct dss_mgr_ops *dss_mgr_ops;
 
 int dss_install_mgr_ops(const struct dss_mgr_ops *mgr_ops)