Teensys can present themselves towards the PC as a Keyboard+Mouse+Joystick device, so with a bit of code and a voltage divider (to get the 5V range down to 3.3V) you can convert the simulator pedals to a joystick axis.
See here: https://www.pjrc.com/teensy/td_joystick.html
How your Teensy appears to your PC while running your program is configured from Arduino's Tools > USB Type menu. The default is Serial, so you'll almost certainly want to change it to one of the other options.