If you want to add an uninstall target you can take a look to the official CMake FAQ at:
https://gitlab.kitware.com/cmake/community/wikis/FAQ#can-i-do-make-uninstall-with-cmake
If you just want a quick way to uninstall all files, just run:
xargs rm < install_manifest.txt
install_manifest.txt file is created when you run make install.