You can uninstall or removes an installed fake-hwclock package itself from Ubuntu 16.04 LTS (Xenial Xerus) through the terminal,
$ sudo apt-get remove fake-hwclock
If you would like to remove fake-hwclock and it's dependent packages which are no longer needed from Ubuntu,
$ sudo apt-get remove --auto-remove fake-hwclock
If you use with purge options to fake-hwclock package all the configuration and dependent packages will be removed.
$ sudo apt-get purge fake-hwclock
If you use purge options along with auto remove, will be removed everything regarding the package, It's really useful when you want to reinstall again.
$ sudo apt-get purge --auto-remove fake-hwclock