boards: nxp: frdm_mcxa156: Support wwdt for NXP frdm_mcxa156 board

Support watchdog for NXP frdm_mcxa156 board.
Test it using samples/drivers/watchdog.

Signed-off-by: Neil Chen <cheng.chen_1@nxp.com>

boards/nxp/frdm_mcxa156/board.c

@@ -212,6 +212,10 @@ static int frdm_mcxa156_init(void)
 	CLOCK_EnableUsbfsClock();
 #endif
 
+#if DT_NODE_HAS_STATUS_OKAY(DT_NODELABEL(wwdt0))
+	CLOCK_SetClockDiv(kCLOCK_DivWWDT0, 1u);
+#endif
+
 	/* Set SystemCoreClock variable. */
 	SystemCoreClock = CLOCK_INIT_CORE_CLOCK;
 

boards/nxp/frdm_mcxa156/doc/index.rst

@@ -72,6 +72,8 @@ The FRDM-MCXA156 board configuration supports the following hardware features:
 +-----------+------------+-------------------------------------+
 | USB       | on-chip    | USB device                          |
 +-----------+------------+-------------------------------------+
+| WATCHDOG  | on-chip    | watchdog                            |
++-----------+------------+-------------------------------------+
 
 Targets available
 ==================

boards/nxp/frdm_mcxa156/frdm_mcxa156.dts

@@ -22,6 +22,7 @@
 		sw1 = &user_button_3;
 		pwm-0 = &flexpwm0_pwm0;
 		mcuboot-button0 = &user_button_2;
+		watchdog0 = &wwdt0;
 	};
 
 	chosen {
@@ -149,6 +150,10 @@ zephyr_udc0: &usb {
 	num-bidir-endpoints = <8>;
 };
 
+&wwdt0 {
+	status = "okay";
+};
+
 &flash {
 	partitions {
 		compatible = "fixed-partitions";

boards/nxp/frdm_mcxa156/frdm_mcxa156.yaml

@@ -25,4 +25,5 @@ supported:
   - pwm
   - usb_device
   - usbd
+  - watchdog
 vendor: nxp