dt-bindings: lt3593: Add function and color properties

Refer to new "function" and "color" properties and mark "label"
as deprecated.
Signed-off-by: Jacek Anaszewski <jacek.anaszewski@gmail.com>
Cc: Daniel Mack <daniel@zonque.org>
Reviewed-by: Rob Herring <robh@kernel.org>

Documentation/devicetree/bindings/leds/leds-lt3593.txt

@@ -9,8 +9,10 @@ The hardware supports only one LED. The properties of this LED are
 configured in a sub-node in the device node.
 
 Optional sub-node properties:
-- label:	A label for the LED. If none is given, the LED will be
-		named "lt3595::".
+- function:		See Documentation/devicetree/bindings/leds/common.txt
+- color:		See Documentation/devicetree/bindings/leds/common.txt
+- label:		A label for the LED. If none is given, the LED will be
+			named "lt3595::" (deprecated)
 - linux,default-trigger: The default trigger for the LED.
 			See Documentation/devicetree/bindings/leds/common.txt
 - default-state:	The initial state of the LED.
@@ -21,12 +23,15 @@ be handled by its own device node.
 
 Example:
 
+#include <dt-bindings/leds/common.h>
+
 led-controller {
 	compatible = "lltc,lt3593";
 	lltc,ctrl-gpios = <&gpio 0 GPIO_ACTIVE_HIGH>;
 
 	led {
-		label = "white:backlight";
+		function = LED_FUNCTION_BACKLIGHT;
+		color = <LED_COLOR_ID_WHITE>;
 		default-state = "on";
 	};
 };