Add configuration option to select VFAT

git-svn-id: svn://svn.code.sf.net/p/nuttx/code/trunk@217 42af7a65-404d-4744-a932-0658087f49c3

Documentation/NuttxPortingGuide.html

@@ -1123,6 +1123,8 @@ The system can be re-made subsequently by just typing <code>make</code>.
      the particular chip or SoC.</li>
   <li><code>CONFIG_ARCH_BOARD_name</code>:
      For use in C code</li>
+  <li><code>CONFIG_ENDIAN_BIG</code>:
+     Define if big endian (default is little endian).</li>
 </ul>
 
 <p>