OMAP: DSS2: move run_test()

Move run_test() from omap_dss_device to omap_dss_driver.

This is part of a larger patch-set, which moves the control from omapdss
driver to the display driver.

Signed-off-by: Tomi Valkeinen <tomi.valkeinen@nokia.com>
diff --git a/drivers/video/omap2/displays/panel-taal.c b/drivers/video/omap2/displays/panel-taal.c
index 0aaaa8a..e6d0954 100644
--- a/drivers/video/omap2/displays/panel-taal.c
+++ b/drivers/video/omap2/displays/panel-taal.c
@@ -820,17 +820,23 @@
 	u8 id1, id2, id3;
 	int r;
 
+	dsi_bus_lock();
+
 	r = taal_dcs_read_1(DCS_GET_ID1, &id1);
 	if (r)
-		return r;
+		goto err;
 	r = taal_dcs_read_1(DCS_GET_ID2, &id2);
 	if (r)
-		return r;
+		goto err;
 	r = taal_dcs_read_1(DCS_GET_ID3, &id3);
 	if (r)
-		return r;
+		goto err;
 
+	dsi_bus_unlock();
 	return 0;
+err:
+	dsi_bus_unlock();
+	return r;
 }
 
 static int taal_memory_read(struct omap_dss_device *dssdev,