package/libdcadec: remove package

Quoting https://github.com/foo86/dcadec

"This program is deprecated!

 This decoder has been fully integrated into FFmpeg master branch and
 further development will continue there. Using FFmpeg for DTS decoding
 is now recommended."

lbdcadec has had no commit oin the past 7+ years now.

Fixes:
http://autobuild.buildroot.net/results/1e63586c91a2670ecac2940f6e9840e6801c32f3/

Signed-off-by: Bernd Kuhls <bernd.kuhls@t-online.de>
[yann.morin.1998@free.fr: amend commit log with age of last activity]
Signed-off-by: Yann E. MORIN <yann.morin.1998@free.fr>
6 files changed