OMAPDSS: handle errors in dss_init_device

Add error handling to dss_init_device(), which has, for some reason,
been missing.

Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
diff --git a/drivers/video/omap2/dss/dss.h b/drivers/video/omap2/dss/dss.h
index a977826..98e8273 100644
--- a/drivers/video/omap2/dss/dss.h
+++ b/drivers/video/omap2/dss/dss.h
@@ -228,7 +228,7 @@
 int dss_resume_all_devices(void);
 void dss_disable_all_devices(void);
 
-void dss_init_device(struct platform_device *pdev,
+int dss_init_device(struct platform_device *pdev,
 		struct omap_dss_device *dssdev);
 void dss_uninit_device(struct platform_device *pdev,
 		struct omap_dss_device *dssdev);