realtek: hog the GS1900 exteral IC reset line

The GPIO line connecting to the reset signals of a board's external ICs
(ethernet phys, RTL8231 expanders, ...) should not be asserted.

As the line is shared between buses, it cannot cleanly be assigned
elsewhere in the devicetree. Let's create a hog to permanently de-assert
the signal, reliably keeping the phys and GPIO expanders on.

Signed-off-by: Sander Vanheule <sander@svanheule.net>

Author: svanheule

target/linux/realtek/dts/rtl8380_zyxel_gs1900.dtsi

@@ -42,6 +42,15 @@
 	};
 };
 
+&gpio0 {
+	ext_reset {
+		gpio-hog;
+		gpios = <1 GPIO_ACTIVE_LOW>;
+		output-low;
+		line-name = "external-peripheral-reset";
+	};
+};
+
 &spi0 {
 	status = "okay";