ARM: dts: imx28-tx28: Pass the memory unit name

Pass the memory unit name in order to fix the following
dtc warning with W=1:

arch/arm/boot/dts/imx28-tx28.dtb: Warning (unit_address_vs_reg): Node /memory has a reg or ranges property, but no unit name
Signed-off-by: NFabio Estevam <fabio.estevam@nxp.com>
Acked-by: NLothar Waßmann <LW@KARO-electronics.de>
Signed-off-by: NShawn Guo <shawnguo@kernel.org>

arch/arm/boot/dts/imx28-tx28.dts

@@ -65,8 +65,8 @@
 		usbotg = &usb0;
 	};
 
-	memory {
-		reg = <0 0>; /* will be filled in by U-Boot */
+	memory@40000000 {
+		reg = <0x40000000 0>; /* will be filled in by U-Boot */
 	};
 
 	onewire {