Keep the ./configure options for xvid in sync.

git-svn-id: svn://svn.mplayerhq.hu/mplayer/trunk@12001 b3059339-0415-0410-9bf9-f77b7e298cf2

DOCS/xml/en/codecs.xml

@@ -506,7 +506,8 @@ then started XviD. So both projects have the same origin.
   </para></step>
 <step><para>
   Recompile <application>MPlayer</application> with
-  <option>--with-xvidcore=<replaceable>/path/to/</replaceable>libxvidcore.a</option>.
+  <option>--with-xvidlibdir=<replaceable>/path/to/</replaceable>libxvidcore.a</option>
+  <option>--with-xvidincdir=<replaceable>/path/to/</replaceable>xvid.h</option>
   </para></step>
 </procedure>
 </sect3>