/usr/lib/linux-tools/4.15.0-1021-gcp/cpupower is in linux-tools-4.15.0-1021-gcp 4.15.0-1021.22~16.04.1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/linux-tools/4.15.0-1021-gcp/../../linux-gcp-tools-4.15.0-1021/cpupower