svn move does not support wild cards. In the SVN editor, they indicate that this command can "Move and schedule a file or directory":
http://svnbook.red-bean.com/en/1.5/svn.ref.svn.c.move.html
Therefore, you need to call svn move for each file in the directory.
I suggest you write a short script that will do this for you or try to use one of the Subversion GUI tools.