[nrf fromtree] samples: doc: convert philosophers sample to code-sample directive

Adopt zephyr:code-sample directive to describe the Dining
Philosophers sample and update reference accordingly.

Signed-off-by: Benjamin Cabé <[email protected]>
(cherry picked from commit a5b7349)

Signed-off-by: Sean Madigan <[email protected]>
(cherry picked from commit c53ed0c)

Author: kartben

samples/boards/arc_secure_services/README.rst

@@ -68,7 +68,7 @@ Currently, in normal application, MPU is not accessible, so no user space and
 mpu-based stack checking. Please copy the specific dts file and def_config
 file to the specific board dir to build normal application.
 
-Here,take :ref:`dining-philosophers-sample` as an example for normal
+Here,take :zephyr:code-sample:`dining-philosophers` as an example for normal
 application.
 
 .. zephyr-app-commands::

samples/philosophers/README.rst

@@ -1,7 +1,8 @@
-.. _dining-philosophers-sample:
+.. zephyr:code-sample:: dining-philosophers
+  :name: Dining Philosophers
+  :relevant-api: semaphore_apis mutex_apis stack_apis thread_apis fifo_apis lifo_apis
 
-Dining Philosophers
-###################
+  Implement a solution to the Dining Philosophers problem using Zephyr kernel services.
 
 Overview
 ********

samples/posix/philosophers/README.rst

@@ -6,7 +6,7 @@
 Overview
 ********
 
-This sample implements Zephyr's :ref:`Dining Philosophers Sample <dining-philosophers-sample>` using the
+This sample implements Zephyr's :zephyr:code-sample:`dining-philosophers` sample using the
 :ref:`POSIX API <posix_support>`. The source code for this sample can be found under
 :file:`samples/posix/philosophers`.
 
@@ -52,5 +52,4 @@ Like the original philosophers sample, the POSIX variant also enables
 Additional Information
 **********************
 
-For additional information, please refer to the
-:ref:`Dining Philosophers Sample <dining-philosophers-sample>`.
+For additional information, please refer to the :zephyr:code-sample:`dining-philosophers` sample.