Hi,
VOXL comes with FastCV installed, the 2 headers can be found in /usr/include/fastcv/ and the libs are in /usr/lib/ :
voxl:/$ find /usr | grep fastcv
/usr/include/fastcv
/usr/include/fastcv/fastcv.h
/usr/include/fastcv/fastcvExt.h
/usr/lib/libfastcvadsp_stub.so
/usr/lib/libfastcvopt.so
/usr/lib/rfsa/adsp/libfastcvadsp.so
/usr/lib/rfsa/adsp/libfastcvadsp_skel.so
G