Detect TPMs

[arunoruto]

Is your feature request related to a problem? Please describe.

TPMs can be nice to spice up the security around priv/pub keys. They are tied to your device and even if the private one leaks, there is no immediate thread.

Describe the solution you'd like

Read out the TPM information. For example, to get the version of the device, one can run

cat /sys/class/tpm/tpm*/tpm_version_major

This can be used again, to enable the ssh-tpm-agent, since it only makes sense to have it running with version 2 (or higher in the future?).

Describe alternatives you've considered

Additional context