arm64: dts: apple: t8015: Add backlight nodes

Add DWI backlight controller nodes for Apple A11 SoC, and enable it for:

- iPhone 8
- iPhone 8 Plus

Signed-off-by: Nick Chan <towinchenmi@gmail.com>
Link: https://lore.kernel.org/r/20250228-dwi-dt-v2-5-69e450bc4bfb@gmail.com
Signed-off-by: Sven Peter <sven@svenpeter.dev>

arch/arm64/boot/dts/apple/t8015-8.dtsi

@@ -11,3 +11,7 @@
 / {
 	chassis-type = "handset";
 };
+
+&dwi_bl {
+	status = "okay";
+};

arch/arm64/boot/dts/apple/t8015.dtsi

@@ -262,6 +262,13 @@
 			reg = <0x2 0x32000000 0 0x8c000>;
 		};
 
+		dwi_bl: backlight@232200080 {
+			compatible = "apple,t8015-dwi-bl", "apple,dwi-bl";
+			reg = <0x2 0x32200080 0x0 0x8>;
+			power-domains = <&ps_dwi>;
+			status = "disabled";
+		};
+
 		pinctrl_ap: pinctrl@233100000 {
 			compatible = "apple,t8015-pinctrl", "apple,pinctrl";
 			reg = <0x2 0x33100000 0x0 0x1000>;