ARM: dts: uniphier: fix no unit name warnings

Fix warnings reported when built with W=1, by DTC 1.4.2 or later:
  Node /memory has a reg or ranges property, but no unit name

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
diff --git a/arch/arm/dts/uniphier-pro4-ref.dts b/arch/arm/dts/uniphier-pro4-ref.dts
index 920fd54..a1fbbdc 100644
--- a/arch/arm/dts/uniphier-pro4-ref.dts
+++ b/arch/arm/dts/uniphier-pro4-ref.dts
@@ -34,7 +34,7 @@
 		usb0 = &usb0;
 	};
 
-	memory {
+	memory@80000000 {
 		device_type = "memory";
 		reg = <0x80000000 0x40000000>;
 	};