boards: frdm_mcxn236: add temperature sensor support

1. enable temperature sensor support
2. verified samples/sensor/die_temp_polling

Signed-off-by: Neil Chen <[email protected]>

Author: NeilChen93

boards/nxp/frdm_mcxn236/frdm_mcxn236.dts

@@ -28,6 +28,7 @@
 		watchdog0 = &wwdt0;
 		pwm-0 = &flexpwm1_pwm0;
 		rtc = &rtc;
+		die-temp0 = &temp0;
 	};
 
 	arduino_header: arduino-connector {

dts/arm/nxp/nxp_mcxn23x_common.dtsi

@@ -729,6 +729,11 @@
 		nxp,references = <&vref 1800>;
 	};
 
+	temp0: temp0 {
+		compatible = "nxp,lpadc-temp40";
+		status = "disabled";
+	};
+
 	lpadc1: lpadc@10e000 {
 		compatible = "nxp,lpc-lpadc";
 		reg = <0x10e000 0x1000>;

samples/sensor/die_temp_polling/boards/frdm_mcxn236.overlay

@@ -0,0 +1,26 @@
+/*
+ * Copyright 2025 NXP
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+#include <zephyr/dt-bindings/adc/adc.h>
+#include <zephyr/dt-bindings/adc/mcux-lpadc.h>
+
+&lpadc0 {
+	status = "okay";
+	#address-cells = <1>;
+	#size-cells = <0>;
+
+	channel@0 {
+		reg = <0>;
+		zephyr,gain = "ADC_GAIN_1";
+		zephyr,reference = "ADC_REF_EXTERNAL0";
+		zephyr,acquisition-time = <ADC_ACQ_TIME(ADC_ACQ_TIME_TICKS, 131)>;
+		zephyr,input-positive = <MCUX_LPADC_CH26A>;
+	};
+};
+
+&temp0 {
+	status = "okay";
+	io-channels = <&lpadc0 0>;
+};