khefin-add-luks-key did not compile with make all

[Chapoly1305]

Describe the bug
khefin-add-luks-key will not be compiled with make all.

To Reproduce
Steps to reproduce the behavior:

1. Download Release 0.6.1
2. make all
3. sudo make install
4. khefinkhefin-add-luks-key: command not found

Expected behavior
In general understanding, khefinkhefin-add-luks-key shall be built with make all.

Environment:
Ubuntu 20.04 GCC9.3

[Chapoly1305]

make add-luks-key
sudo make install
is needed for this binary to be built and installed.