doc: sample: mpu Update documentation

Update documentation to new shell commands.

Signed-off-by: Aaron Tsui <aaron.tsui@outlook.com>

samples/mpu/mpu_test/README.rst

@@ -26,18 +26,6 @@ This project can be built and executed as follows:
    :goals: build flash
    :compact:
 
-Reset the board and you should be able to see on the corresponding
-Serial Port the following message:
-
-.. code-block:: console
-
-   ***** BOOTING ZEPHYR OS v1.7.99 - BUILD: Mar  9 2017 13:01:59 *****
-   *** MPU test options ***
-   1 - Read a reserved address in the memory map
-   2 - Write in to boot FLASH/ROM
-   3 - Run code located in RAM
-   Select an option:
-
 To build the single thread version, use the supplied configuration file for
 single thread: :file:`prj_single.conf`:
 
@@ -57,12 +45,11 @@ Sample Output
 
 .. code-block:: console
 
-   ***** BOOTING ZEPHYR OS v1.7.99 - BUILD: May 12 2017 09:47:02 *****
-   shell> select mpu_test
-   mpu_test> read
-   ***** BUS FAULT *****
-     Executing thread ID (thread): 0x200003b8
-     Faulting instruction address:  0x290
-     Precise data bus error
-     Address: 0x24000000
-   Fatal fault in thread 0x200003b8! Aborting.
+  uart:~$ mpu read
+  ***** BUS FAULT *****
+    Precise data bus error
+    BFAR Address: 0x24000000
+  ***** Hardware exception *****
+  Current thread ID = 0x20000400
+  Faulting instruction address = 0x80004a8
+  Fatal fault in thread 0x20000400! Aborting.