Setup fingerprint reader for T480

1. Reset the fingerprint data in the BIOS
2. Reset the fingerprint firmware like so:

$ sudo systemctl stop python3-validity
$ sudo validity-sensors-firmware
$ sudo python3 /usr/share/python-validity/playground/factory-reset.py

# At some of the above points you may get a 'device busy' error,
# depending on how systemctl plays along. Kill offending processes if
# necessary, or re-run the systemctl stop python3-validity command,
# in case it has automatically been restarted, or or kill other
# offending processes.

$ sudo systemctl start python3-validity
$ fprintd-enroll

3. Activate the fingerprint reader for a login-manager like greetd:

auth sufficient pam_fprint.so

Sources: https://github.com/uunicorn/python-validity