You can't change the USB information programmatically. The fact that you're referencing
/dev/ttyUSB* means you have hardware USB interface chips (CH340, PL2302, FT232, etc) which you can't change from your sketch (some can be adjusted using tools provided by the chip manufacturer though, so you may be able to tweak it using that).
Instead your only option is to have some kind of "fingerprint" that software on your computer can request from your firmware. If you stick to a common serial protocol for all your firmwares you can implement a standard "Firmware Version" command which will respond with what code and version you have installed.
It's up to you to decide how best to implement such a system, of course.