ARM: dts: imx6ul-isiot: Add backlight support for lcdif

This patch add support for lcdif backlight on Is.IoT MX6UL
variant boards.

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/imx6ul-isiot.dtsi

@@ -52,6 +52,29 @@ memory {
 	chosen {
 		stdout-path = &uart1;
 	};
+
+	backlight {
+		compatible = "pwm-backlight";
+		pwms = <&pwm8 0 100000>;
+		brightness-levels = < 0  1  2  3  4  5  6  7  8  9
+				     10 11 12 13 14 15 16 17 18 19
+				     20 21 22 23 24 25 26 27 28 29
+				     30 31 32 33 34 35 36 37 38 39
+				     40 41 42 43 44 45 46 47 48 49
+				     50 51 52 53 54 55 56 57 58 59
+				     60 61 62 63 64 65 66 67 68 69
+				     70 71 72 73 74 75 76 77 78 79
+				     80 81 82 83 84 85 86 87 88 89
+				     90 91 92 93 94 95 96 97 98 99
+				    100>;
+		default-brightness-level = <100>;
+	};
+};
+
+&pwm8 {
+	pinctrl-names = "default";
+	pinctrl-0 = <&pinctrl_pwm8>;
+	status = "okay";
 };
 
 &uart1 {
@@ -72,6 +95,12 @@ &usdhc1 {
 };
 
 &iomuxc {
+	pinctrl_pwm8: pwm8grp {
+		fsl,pins = <
+			MX6UL_PAD_ENET1_RX_ER__PWM8_OUT   0x110b0
+		>;
+	};
+
 	pinctrl_uart1: uart1grp {
 		fsl,pins = <
 			MX6UL_PAD_UART1_TX_DATA__UART1_DCE_TX 0x1b0b1