arm64: dts: meson-axg: s400: add cts-rts to the bluetooth uart

The uart used with bluetooth chipset on the s400 has flow control
available. Let's enable it.
Signed-off-by: Jerome Brunet <jbrunet@baylibre.com>
Reviewed-by: Neil Armstrong <narmstrong@baylibre.com>
Signed-off-by: Kevin Hilman <khilman@baylibre.com>

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

@@ -543,8 +543,9 @@ &toddr_c {
 
 &uart_A {
 	status = "okay";
-	pinctrl-0 = <&uart_a_pins>;
+	pinctrl-0 = <&uart_a_pins>, <&uart_a_cts_rts_pins>;
 	pinctrl-names = "default";
+	uart-has-rtscts;
 };
 
 &uart_AO {