Switch EMC2101 to ESP32 PWM

[korbin]

To save cost, complexity, and a unique component:

• Pull fan PWM to 5V (board gets plugged in, fan goes to 100%)
• Add additional level shifter (TXU0304 or TXU0202) from 3V3 -> 5V
• Use ESP32 PWM signal to drive level shifter (or MOSFETs) to set fan speed
• Use ESP32 PWM counter/GPIO/timer/whatever peripheral to measure fan speed

[skot]

I like this idea for if/when we don't need the EMC2101 for temp diode reading anymore. Supposedly the BM1368 has the ability to read the temp (and voltage) out over there serial port. This needs a little more hacking/dev to get working