The LIS2DH12 driver performed an unnecessary endianness conversion, as
data from the sensor was already coming in little-endian format. The
MMA8652FC driver is now using the rev16 opcode to perform the swap
rather than doing all the bitshuffling operations in multiple steps.
Made the display on/off mechanism a bit more self-descriptive by
replacing bare true/false values with an enum with more appropriate
value names. OLED automatic turn-off logic has been cleaned up,
along with minor updates to the OLED initialisation sequence.
