ffmpeg: enable x86_64
ffmpeg: enable x86_64

* build with fPIC on x86_64
* also build libavresample

haikuports/haikuports,koletzky/haikuports,Begasus/haikuports,haikuports/haikuports,koletzky/haikuports,nielx/haikuports,nielx/haikuports,miqlas/haikuports,moochris/haikuports,Begasus/haikuports,miqlas/haikuports,Begasus/haikuports,nielx/haikuports,haikuports/haikuports,haikuports/haikuports,moochris/haikuports,haikuports/haikuports,koletzky/haikuports,Begasus/haikuports,moochris/haikuports,miqlas/haikuports,Begasus/haikuports