arm64: dts: renesas: hihope-rzg2-ex: Enable backlight

This patch enables backlight support.
Signed-off-by: Biju Das <biju.das@bp.renesas.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Link: https://lore.kernel.org/r/1570029619-43238-8-git-send-email-biju.das@bp.renesas.comSigned-off-by: Geert Uytterhoeven <geert+renesas@glider.be>

arch/arm64/boot/dts/renesas/hihope-rzg2-ex.dtsi

@@ -13,6 +13,14 @@ aliases {
 	chosen {
 		bootargs = "ignore_loglevel rw root=/dev/nfs ip=on";
 	};
+
+	backlight {
+		compatible = "pwm-backlight";
+		pwms = <&pwm0 0 50000>;
+
+		brightness-levels = <0 2 8 16 32 64 128 255>;
+		default-brightness-level = <6>;
+	};
 };
 
 &avb {
@@ -82,4 +90,16 @@ can1_pins: can1 {
 		groups = "can1_data";
 		function = "can1";
 	};
+
+	pwm0_pins: pwm0 {
+		groups = "pwm0";
+		function = "pwm0";
+	};
+};
+
+&pwm0 {
+	pinctrl-0 = <&pwm0_pins>;
+	pinctrl-names = "default";
+
+	status = "okay";
 };