samples: drivers: dac: support frdm_mcxn947 dac example

add support frdm_mcxn947 dac example

Signed-off-by: Zhaoxiang Jin <Zhaoxiang.Jin_1@nxp.com>
diff --git a/samples/drivers/dac/boards/frdm_mcxn947.overlay b/samples/drivers/dac/boards/frdm_mcxn947.overlay
new file mode 100644
index 0000000..183cad3
--- /dev/null
+++ b/samples/drivers/dac/boards/frdm_mcxn947.overlay
@@ -0,0 +1,17 @@
+/*
+ * Copyright 2024 NXP
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+/ {
+
+    /*
+    * Please note on the FRDM-MCXN947 board, DAC0 output signal port is J1-4.
+    */
+    zephyr,user {
+        dac = <&dac0>;
+        dac-channel-id = <0>;
+        dac-resolution = <12>;
+    };
+};