ARM: dts: imx6dl: prtvt7: Adjust default backlight brightness to 65

This commit changes the default brightness level of the backlight on the
prtvt7 device from 20 to 65, roughly equivalent to 75% of the maximum
brightness level defined in the "brightness-levels" property.

The adjustment provides a more optimal default brightness for the
device, improving the overall user experience.
Signed-off-by: Robin van der Gracht <robin@protonic.nl>
Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>

arch/arm/boot/dts/imx6dl-prtvt7.dts

@@ -24,7 +24,7 @@ backlight_lcd: backlight-lcd {
 		compatible = "pwm-backlight";
 		pwms = <&pwm1 0 500000 0>;
 		brightness-levels = <0 20 81 248 1000>;
-		default-brightness-level = <20>;
+		default-brightness-level = <65>;
 		num-interpolated-steps = <21>;
 		power-supply = <&reg_bl_12v0>;
 	};