ARM: dts: i.MX51 babbage: Support diagnostic LED

The D25 LED controlled by gpio on the i.MX51 babbage
board is a diagnostic LED according to the board design.
This patch adds the relevant device tree nodes to the
i.MX51 babbage device tree file to support this LED.
Signed-off-by: Liu Ying <Ying.Liu@freescale.com>
Signed-off-by: Shawn Guo <shawn.guo@linaro.org>

arch/arm/boot/dts/imx51-babbage.dts

@@ -81,6 +81,17 @@ power {
 		};
 	};
 
+	leds {
+		compatible = "gpio-leds";
+		pinctrl-names = "default";
+		pinctrl-0 = <&pinctrl_gpio_leds>;
+
+		led-diagnostic {
+			label = "diagnostic";
+			gpios = <&gpio2 6 GPIO_ACTIVE_HIGH>;
+		};
+	};
+
 	sound {
 		compatible = "fsl,imx51-babbage-sgtl5000",
 			     "fsl,imx-audio-sgtl5000";
@@ -344,6 +355,12 @@ MX51_PAD_EIM_A20__GPIO2_14 0x85 /* Reset */
 			>;
 		};
 
+		pinctrl_gpio_leds: gpioledsgrp {
+			fsl,pins = <
+				MX51_PAD_EIM_D22__GPIO2_6		0x80000000
+			>;
+		};
+
 		pinctrl_i2c2: i2c2grp {
 			fsl,pins = <
 				MX51_PAD_KEY_COL4__I2C2_SCL		0x400001ed