ARM: dts: dm8168: Add missing unit name to memory nodes

This patch fixes the following DTC warnings:

"Node /memory has a reg or ranges property, but no unit name"
Signed-off-by: Javier Martinez Canillas <javier@osg.samsung.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>

arch/arm/boot/dts/dm8168-evm.dts

@@ -12,7 +12,7 @@ / {
 	model = "DM8168 EVM";
 	compatible = "ti,dm8168-evm", "ti,dm8168";
 
-	memory {
+	memory@80000000 {
 		device_type = "memory";
 		reg = <0x80000000 0x40000000	/* 1 GB */
 		       0xc0000000 0x40000000>;	/* 1 GB */