cmake: code relocation setting.

With code relocation directives passed to the gen_relocate_app.py script
using generated file, then each directive can be place on individual
line in the file and thus free up the `|` character as separator.

Furthermore, a multi-line file with each directive on separate line is
also more user-readable, making debugging easier.

Signed-off-by: Torsten Rasmussen <Torsten.Rasmussen@nordicsemi.no>