Add support for Nezter encoders to ODrive firmware

[cindyli-13]

The ODrive firmware already has support for absolute SPI encoders, however we'll need to add proper support for our Nezter DS-25 encoders to be used with our ODrive controllers. This task involves understanding how the ODrive firmware works (specifically how their encoder interface is structured) and modifying it to allow Nezter encoders to be used.

Links:

• ODrive official website
• Our ODrive repo
• Nezter DS-25 encoder datasheet
• Our Netzer driver using Mbed (currently WIP)