autotools: set CMake libraries directly in configure.ac

[madebr]

Build CMake list containing CMake targets in configure.ac

I tested this with:

mkdir build
cd build
../configure --prefix=$PWD/prefix --enable-music-mod-modplug-shared=no --enable-music-mod-xmp-shared=no --enable-music-midi-fluidsynth-shared=no --enable-music-gme-shared=no --enable-music-ogg-vorbis-shared=no --enable-music-ogg-tremor-shared=no --enable-music-flac-libflac-shared=no --enable-music-mp3-mpg123-shared=no --enable-music-opus-shared=no --enable-music-wavpack-shared=no
make
make install
cmake -S ../cmake/test -B /tmp/sdl2-mixer-autotools-cmake-test-build --fresh -DCMAKE_PREFIX_PATH=$PWD/prefix
cmake --build /tmp/sdl2-mixer-autotools-cmake-test-build

Fixes #655

[sezero]

With my aututools glasses only, looks good to me.