arm64: dts: amlogic: t7: khadas-vim4: add PWM-driven status LED

The VIM4 board exposes a status LED wired to the PWM_AO_C_D output.
Enable the pwm_ao_cd controller with its pinmux, and declare a
pwm-leds node with a heartbeat trigger.

Signed-off-by: Ronald Claveau <linux-kernel-dev@aliel.fr>
Link: https://patch.msgid.link/20260513-add-kvim4-sysled-v2-3-3ec9779e8875@aliel.fr
Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>

Author: rclaveau-tech

arch/arm64/boot/dts/amlogic/amlogic-t7-a311d2-khadas-vim4.dts

@@ -53,6 +53,16 @@
 		regulator-always-on;
 	};
 
+	pwm-leds {
+		compatible = "pwm-leds";
+
+		status {
+			linux,default-trigger="heartbeat";
+			max-brightness = <255>;
+			pwms = <&pwm_ao_cd 0 30040 0>;
+		};
+	};
+
 	sd_3v3: regulator-sdcard-3v3 {
 		compatible = "regulator-fixed";
 		regulator-name = "SD_3V3";
@@ -163,6 +173,12 @@
 	pinctrl-names = "default";
 };
 
+&pwm_ao_cd {
+	status = "okay";
+	pinctrl-0 = <&pwm_ao_c_d_pins>;
+	pinctrl-names = "default";
+};
+
 /* SDIO */
 &sd_emmc_a {
 	status = "okay";