ARM64: dts: meson-axg: enable the UART_A controller

The UART_A is connected to a BT module on the S400 board.
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

@@ -14,6 +14,7 @@ / {
 
 	aliases {
 		serial0 = &uart_AO;
+		serial1 = &uart_A;
 	};
 };
 
@@ -24,6 +25,12 @@ &ethmac {
 	pinctrl-names = "default";
 };
 
+&uart_A {
+	status = "okay";
+	pinctrl-0 = <&uart_a_pins>;
+	pinctrl-names = "default";
+};
+
 &uart_AO {
 	status = "okay";
 	pinctrl-0 = <&uart_ao_a_pins>;