/usr/lib/linux-tools/4.4.0-78-generic/x86_energy_perf_policy is in linux-tools-4.4.0-78-generic 4.4.0-78.99~14.04.2.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/linux-tools/4.4.0-78-generic/../../linux-lts-xenial-tools-4.4.0-78/x86_energy_perf_policy