ARM: socfpga: socrates: add gpio-leds

The SOCrates has three HPS LEDs that can be turned on/off via gpio.
Use the first one has heartbeat and add the other two as free LEDs.
Signed-off-by: NSteffen Trumtrar <s.trumtrar@pengutronix.de>
Signed-off-by: NDinh Nguyen <dinguyen@opensource.altera.com>

arch/arm/boot/dts/socfpga_cyclone5_socrates.dts

@@ -30,6 +30,9 @@
 		device_type = "memory";
 		reg = <0x0 0x40000000>; /* 1GB */
 	};
+
+	leds: gpio-leds {
+	};
 };
 
 &gmac1 {
@@ -53,6 +56,26 @@
 	};
 };
 
+&leds {
+	compatible = "gpio-leds";
+
+	led@0 {
+		label = "led:green:heartbeat";
+		gpios = <&porta 28 1>;
+		linux,default-trigger = "heartbeat";
+	};
+
+	led@1 {
+		label = "led:green:D7";
+		gpios = <&portb 19 1>;
+	};
+
+	led@2 {
+		label = "led:green:D8";
+		gpios = <&portb 25 1>;
+	};
+};
+
 &mmc {
 	status = "okay";
 };