* Updated encoder.c so that split encoders are indexed based on left hand encoders first.
This ensures when swapping master sides that code logic based on encoder index doesn't change.
PR Review fixes
* Removed extra define
* Remove the need to set NUM_OF_ENCODERS
Instead, calculate the size of the array, and use that instead
* Add hack for split common support
* Remove NUM_OF_ENCODERS from keyboard config
Can be reverted, if needed