8254 library: Figure out how to detect what mode the PIT is running in

[joncampbell123]

Current code requires writing the PIT 0 counter to put it into a mode where the wait functions and counting/delay code can time properly, because DOSBox-X and most motherboards put it into a mode that counts down by 2 (throwing off our code).

What would be nice is if the 8254 library had a variable to track the PIT mode so that it can follow along if it knows the timer is in that PIT mode (count by 2) instead of requiring the host program to reprogram the PIT timer. It would also be nice if the 8254 library at probe time could automatically detect that PIT 0 is in this mode.