powerpc/mpc512x: add platform code for MPC5125.

Tested on MPC5125 Tower evaluation board with
mpc512x_defconfig compile configuration.

In detail, supports for:
- PSC / UART
- RTC
- ETH
- DIU
- I2C

Signed-off-by: Matteo Facchinetti <matteo.facchinetti@sirius-es.it>
Signed-off-by: Anatolij Gustschin <agust@denx.de>
diff --git a/arch/powerpc/boot/dts/mpc5121ads.dts b/arch/powerpc/boot/dts/mpc5121ads.dts
index f269b13..7d3cb79 100644
--- a/arch/powerpc/boot/dts/mpc5121ads.dts
+++ b/arch/powerpc/boot/dts/mpc5121ads.dts
@@ -13,7 +13,7 @@
 
 / {
 	model = "mpc5121ads";
-	compatible = "fsl,mpc5121ads";
+	compatible = "fsl,mpc5121ads", "fsl,mpc5121";
 
 	nfc@40000000 {
 		/*