sound-theme-freedesktop: fix configure

oe-core's
commit 79ea036de331bde65a88fb777647dc099ef05acf
Author: Richard Purdie <richard.purdie@linuxfoundation.org>
Date:   Sun Mar 2 17:36:38 2014 +0000

    autotools: Limit aclocal files to those in dependencies

makes explicit depencies mandatory

Signed-off-by: Andreas Müller <schnitzeltony@googlemail.com>