ARM: dts: imx7-colibri: specify backlight GPIO

The Colibri standard defines SODIMM 71 as backlight enable
GPIO. Assign the GPIO to the backlight node in the module
level device tree.
Signed-off-by: Stefan Agner <stefan@agner.ch>
Reviewed-by: Fabio Estevam <fabio.estevam@nxp.com>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>

arch/arm/boot/dts/imx7-colibri.dtsi

@@ -43,7 +43,10 @@
 / {
 	bl: backlight {
 		compatible = "pwm-backlight";
+		pinctrl-names = "default";
+		pinctrl-0 = <&pinctrl_gpio_bl_on>;
 		pwms = <&pwm1 0 5000000 0>;
+		enable-gpios = <&gpio5 1 GPIO_ACTIVE_HIGH>;
 	};
 
 	reg_module_3v3: regulator-module-3v3 {
@@ -360,7 +363,6 @@ pinctrl_gpio2: gpio2-grp { /* On X22 Camera interface */
 		fsl,pins = <
 			MX7D_PAD_ECSPI2_SS0__GPIO4_IO23		0x14 /* SODIMM 65 */
 			MX7D_PAD_SD1_CD_B__GPIO5_IO0		0x74 /* SODIMM 69 */
-			MX7D_PAD_SD1_WP__GPIO5_IO1		0x14 /* SODIMM 71 */
 			MX7D_PAD_I2C4_SDA__GPIO4_IO15		0x14 /* SODIMM 75 */
 			MX7D_PAD_ECSPI1_MISO__GPIO4_IO18	0x14 /* SODIMM 79 */
 			MX7D_PAD_I2C3_SCL__GPIO4_IO12		0x14 /* SODIMM 81 */
@@ -436,6 +438,12 @@ MX7D_PAD_GPIO1_IO15__FLEXCAN2_TX	0x59
 		>;
 	};
 
+	pinctrl_gpio_bl_on: gpio-bl-on {
+		fsl,pins = <
+			MX7D_PAD_SD1_WP__GPIO5_IO1		0x14 /* SODIMM 71 */
+		>;
+	};
+
 	pinctrl_gpmi_nand: gpmi-nand-grp {
 		fsl,pins = <
 			MX7D_PAD_SD3_CLK__NAND_CLE		0x71