arm64: dts: uniphier: add GPIO hog definition for PXs3

Commit 15e85695 ("arm64: dts: uniphier: add GPIO hog definition")
missed to update the PXs3 DTS for some reason.  Do it now.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>

arch/arm64/boot/dts/socionext/uniphier-pxs3-ref.dts

@@ -45,6 +45,14 @@ &serial0 {
 	status = "okay";
 };
 
+&gpio {
+	xirq4 {
+		gpio-hog;
+		gpios = <UNIPHIER_GPIO_IRQ(4) 0>;
+		input;
+	};
+};
+
 &i2c0 {
 	status = "okay";
 };