Drop dependency on cpp, leftover from the xbase-clients split.
drwxr-xr-x - debian
drwxr-xr-x - setxkbmap
drwxr-xr-x - xkbcomp
drwxr-xr-x - xkbevd
drwxr-xr-x - xkbprint
drwxr-xr-x - xkbutils