ARM: dts: omap4: 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/omap4-sdp.dts

@@ -14,7 +14,7 @@
 	model = "TI OMAP4 SDP board";
 	compatible = "ti,omap4-sdp", "ti,omap4430", "ti,omap4";
 
-	memory {
+	memory@80000000 {
 		device_type = "memory";
 		reg = <0x80000000 0x40000000>; /* 1 GB */
 	};