Remove the "lmax" OptionDef. The equally named AVOption takes over its function.

Remove the "lmax" OptionDef. The equally named AVOption takes over its function.
A unit change is involved, but as AVOption parameters are now parsed with
ff_eval2(), you can use the QP2LAMBDA constant to ease the change:
ffmpeg -i src.ext -lmax 21*QP2LAMBDA dst.ext

Originally committed as revision 6367 to svn://svn.ffmpeg.org/ffmpeg/trunk