When both SIMD/NEON optimized and non-SIMD resamplers are built
soxr uses libavutil to do runtime CPU detection to switch
between these.
Avoid that by enabling only one of them depending on NEON
availability.
Also explicitly disable AVFFT to avoid picking up a dependency
on libavcodec.
Signed-off-by: Matthias Reichl <hias@horus.com>
c0c0c08f32