ARM: dts: imx6qdl-icore: Add backlight support for lvds

This patch add support for lvds backlight on i.CoreM6 QDL
variant boards.

Cc: Domenico Acri <domenico.acri@engicam.com>
Cc: Matteo Lisi <matteo.lisi@engicam.com>
Cc: Michael Trimarchi <michael@amarulasolutions.com>
Signed-off-by: Jagan Teki <jagan@amarulasolutions.com>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>

arch/arm/boot/dts/imx6qdl-icore.dtsi

@@ -48,6 +48,13 @@ memory {
 		reg = <0x10000000 0x80000000>;
 	};
 
+	backlight {
+		compatible = "pwm-backlight";
+		pwms = <&pwm3 0 100000>;
+		brightness-levels = <0 4 8 16 32 64 128 255>;
+		default-brightness-level = <7>;
+	};
+
 	reg_3p3v: regulator-3p3v {
 		compatible = "regulator-fixed";
 		regulator-name = "3P3V";
@@ -136,6 +143,12 @@ &i2c3 {
 	status = "okay";
 };
 
+&pwm3 {
+	pinctrl-names = "default";
+	pinctrl-0 = <&pinctrl_pwm3>;
+	status = "okay";
+};
+
 &uart4 {
 	pinctrl-names = "default";
 	pinctrl-0 = <&pinctrl_uart4>;
@@ -246,6 +259,12 @@ MX6QDL_PAD_KEY_ROW0__UART4_RX_DATA 0x1b0b1
 		>;
 	};
 
+	pinctrl_pwm3: pwm3grp {
+		fsl,pins = <
+			MX6QDL_PAD_SD4_DAT1__PWM3_OUT 0x1b0b1
+		>;
+	};
+
 	pinctrl_usbotg: usbotggrp {
 		fsl,pins = <
 			MX6QDL_PAD_GPIO_1__USB_OTG_ID 0x17059