powerpc/mpc5121: correct DIU compatible property

The DIU driver should bind against "fsl,mpc5121-diu"
directly. Add this compatible property to the match
table and fix DTS and platform code accordingly.

Signed-off-by: Anatolij Gustschin <agust@denx.de>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
diff --git a/drivers/video/fsl-diu-fb.c b/drivers/video/fsl-diu-fb.c
index 72d68b3..4637bcb 100644
--- a/drivers/video/fsl-diu-fb.c
+++ b/drivers/video/fsl-diu-fb.c
@@ -1633,6 +1633,11 @@
 #endif
 
 static struct of_device_id fsl_diu_match[] = {
+#ifdef CONFIG_PPC_MPC512x
+	{
+		.compatible = "fsl,mpc5121-diu",
+	},
+#endif
 	{
 		.compatible = "fsl,diu",
 	},