ARM64: dts: meson-gxl-p23x: Add uart pinctrl

Add pinctrl attribute to p23x uart node.
Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
Signed-off-by: Kevin Hilman <khilman@baylibre.com>

arch/arm64/boot/dts/amlogic/meson-gxl-s905d-p23x.dtsi

@@ -58,6 +58,9 @@ memory@0 {
 	};
 };
 
+/* This UART is brought out to the DB9 connector */
 &uart_AO {
 	status = "okay";
+	pinctrl-0 = <&uart_ao_a_pins>;
+	pinctrl-names = "default";
 };