ARM64: dts: meson-axg: complete the pinctrl info for UART_AO_A

Explictly request the pinctrl info for the UART_AO_A controller,
otherwise we may need to rely on bootloader for the initialization.
Acked-by: Jerome Brunet <jbrunet@baylibre.com>
Signed-off-by: Yixun Lan <yixun.lan@amlogic.com>
Signed-off-by: Kevin Hilman <khilman@baylibre.com>

arch/arm64/boot/dts/amlogic/meson-axg-s400.dts

@@ -26,6 +26,8 @@ &ethmac {
 
 &uart_AO {
 	status = "okay";
+	pinctrl-0 = <&uart_ao_a_pins>;
+	pinctrl-names = "default";
 };
 
 &ir {