ARM: sunxi: make the leds' names conform to the current naming convention

Quoting from Documentation/leds/leds-class.txt:

    LED Device Naming
    =================

    Is currently of the form:

    "devicename:colour:function"
Signed-off-by: Emilio López <emilio@elopez.com.ar>
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>

arch/arm/boot/dts/sun4i-a10-cubieboard.dts

@@ -76,12 +76,12 @@ leds {
 		pinctrl-0 = <&led_pins_cubieboard>;
 
 		blue {
-			label = "cubieboard::blue";
+			label = "cubieboard:blue:usr";
 			gpios = <&pio 7 21 0>; /* LED1 */
 		};
 
 		green {
-			label = "cubieboard::green";
+			label = "cubieboard:green:usr";
 			gpios = <&pio 7 20 0>; /* LED2 */
 			linux,default-trigger = "heartbeat";
 		};