ARM: dts: BCM53573: Add Tenda AC9 2 GHz LED

It's connected to a GPIO pin of an extra controller placed on the PCIe
card.
Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>

arch/arm/boot/dts/bcm47189-tenda-ac9.dts

@@ -48,6 +48,16 @@ system {
 		};
 	};
 
+	pcie0_leds {
+		compatible = "gpio-leds";
+
+		2ghz {
+			label = "bcm53xx:blue:2ghz";
+			gpios = <&pcie0_chipcommon 3 GPIO_ACTIVE_HIGH>;
+			linux,default-trigger = "default-off";
+		};
+	};
+
 	gpio-keys {
 		compatible = "gpio-keys";
 		#address-cells = <1>;