ARM: dts: sun9i: optimus: Enable Reduced Serial Bus controller

Signed-off-by: Chen-Yu Tsai <wens@csie.org>
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>

arch/arm/boot/dts/sun9i-a80-optimus.dts

@@ -196,6 +196,10 @@ led_r_pins_optimus: led-pins@1 {
 	};
 };
 
+&r_rsb {
+	status = "okay";
+};
+
 &uart0 {
 	pinctrl-names = "default";
 	pinctrl-0 = <&uart0_pins_a>;