This reverts commit a87b17f3283aada762820f1b797eeb7a2dff6c61.
This reduces the amount of non LGPL code, making a relicensing to LGPL
easier
Conflicts:
libavfilter/vf_yadif.c
libavfilter/x86/yadif.c
libavfilter/x86/yadif_template.c
libavfilter/yadif.h
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>