ARM: dts: imx6dl-aristainetos: enable backlight PWM explicitly

All PWM users should explicitly enable the used PWMs in their device tree
so they can be disabled by default in imx6qdl.dtsi.
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
Signed-off-by: Shawn Guo <shawn.guo@linaro.org>

arch/arm/boot/dts/imx6dl-aristainetos_4.dts

@@ -83,3 +83,7 @@ &i2c2 {
 &ipu1_di0_disp0 {
 	remote-endpoint = <&display0_in>;
 };
+
+&pwm1 {
+	status = "okay";
+};

arch/arm/boot/dts/imx6dl-aristainetos_7.dts

@@ -72,3 +72,7 @@ &i2c2 {
 &ipu1_di0_disp0 {
 	remote-endpoint = <&display0_in>;
 };
+
+&pwm3 {
+	status = "okay";
+};