mega-manual: Added the new mars appendix to the sdk-manual build section.

(From yocto-docs rev: 5e9e7553260e7c684f30fd2565ba8c03b8cd0462)

Signed-off-by: Scott Rifenbark <srifenbark@gmail.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

documentation/mega-manual/mega-manual.xml

@@ -123,6 +123,8 @@
         xmlns:xi="http://www.w3.org/2003/XInclude" href="../sdk-manual/sdk-appendix-obtain.xml"/>
     <xi:include
         xmlns:xi="http://www.w3.org/2003/XInclude" href="../sdk-manual/sdk-appendix-customizing.xml"/>
+    <xi:include
+        xmlns:xi="http://www.w3.org/2003/XInclude" href="../sdk-manual/sdk-appendix-mars.xml"/>
 
 <!-- Includes bsp-guide title image and then bsp-guide chapters -->