ARM: dtsi: axp81x: add GPIO DT node

This adds DT node for the GPIO/pinctrl part present in AXP813/AXP818.
Signed-off-by: Quentin Schulz <quentin.schulz@free-electrons.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Chen-Yu Tsai <wens@csie.org>
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>

arch/arm/boot/dts/axp81x.dtsi

@@ -48,6 +48,12 @@ &axp81x {
 	interrupt-controller;
 	#interrupt-cells = <1>;
 
+	axp_gpio: axp-gpio {
+		compatible = "x-powers,axp813-gpio";
+		gpio-controller;
+		#gpio-cells = <2>;
+	};
+
 	regulators {
 		/* Default work frequency for buck regulators */
 		x-powers,dcdc-freq = <3000>;