ARM: dts: uniphier: sync with Linux 4.16-rc5

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
diff --git a/arch/arm/dts/uniphier-pxs3-ref.dts b/arch/arm/dts/uniphier-pxs3-ref.dts
index f549610..0463a8f 100644
--- a/arch/arm/dts/uniphier-pxs3-ref.dts
+++ b/arch/arm/dts/uniphier-pxs3-ref.dts
@@ -45,6 +45,14 @@
 	status = "okay";
 };
 
+&serial2 {
+	status = "okay";
+};
+
+&serial3 {
+	status = "okay";
+};
+
 &gpio {
 	xirq4 {
 		gpio-hog;