lang/squeak: Fix build in 14.0-current
The lang/squeak ports assume B576000 and B1152000.
Lack of B576000 and B1152000 at /usr/include/sys/_termios.h, lang/squeak is
broken at 14.0-Current.
While here, add missing USES, dependencies, reorder variables, etc.
PR: 254456
Submitted by: takeshi.mutoh@gmail.com (maintainer)