/usr/bin/powerpc-linux-gnu-gnatprep is in gnat-5-powerpc-linux-gnu 5.5.0-12ubuntu1cross1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/bin/powerpc-linux-gnu-gnatprep-5
/usr/bin/powerpc-linux-gnu-gnatprep-5