samples: drivers: dac: Enable dac example on lpcxpresso55s36 board

Added overlay for lpcxpresso55s36, updated README.rst

Signed-off-by: Albort Xue <yao.xue@nxp.com>

samples/drivers/dac/README.rst

@@ -209,6 +209,19 @@ also can run for the
    :goals: build flash
    :compact:
 
+Building and Running for NXP LPCXpresso55S36
+============================================
+The sample can be built and executed for the :ref:`lpcxpresso55s36` as
+follows:
+
+.. zephyr-app-commands::
+   :zephyr-app: samples/drivers/dac
+   :board: lpcxpresso55s36
+   :goals: build flash
+   :compact:
+
+DAC output is available on connector J12 pin 4.
+
 Sample output
 =============
 

samples/drivers/dac/boards/lpcxpresso55s36.overlay

@@ -0,0 +1,13 @@
+/*
+ * Copyright 2023 NXP
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+/ {
+    zephyr,user {
+        dac = <&dac0>;
+        dac-channel-id = <0>;
+        dac-resolution = <12>;
+    };
+};

samples/drivers/dac/sample.yaml

@@ -42,6 +42,7 @@ tests:
       - stm32f3_disco
       - stm32l562e_dk
       - twr_ke18f
+      - lpcxpresso55s36
     depends_on: dac
     integration_platforms:
       - nucleo_l152re