Do not ship files with very generic names

[slyon]

Some files of this package are not namespaced properly and should be excluded.

We then need to clarify with upstream if those generic files are actually needed and how we can find a better namespaced place for them.

/etc/card-defs.xml
/usr/lib/aarch64-linux-gnu/pkgconfig/config.pc

[slyon]

config.pc is being dropped (via debian/not-installed and AudioReach/audioreach-conf#92).

While we introduce symlinks for the default XML configuration and backwards compatibility:

# default config
lrwxrwxrwx root/root         0 2026-09-02 13:05 ./etc/audioreach/card-defs.xml -> /usr/share/audioreach/X1E80100/card-defs.xml

# backwards compat
lrwxrwxrwx root/root         0 2026-09-02 13:05 ./etc/card-defs.xml -> audioreach/card-defs.xml
lrwxrwxrwx root/root         0 2026-09-02 13:05 ./etc/acdbdata -> /usr/share/audioreach/acdbdata

This avoids any conffiles and provides full backwards compatibility, while figuring out the best upstream approach: AudioReach/audioreach-conf#90