I2C temperature sensor example.

This example project uses the EFM32 CMSIS and emlib including DVK BSP
(board support package) and demonstrates the use of the I2C bus accessing
the temperature sensor on the DVK.

The following configuration is possible:

- Joystick push toggles between Fahrenheit and Celsius display mode.

Board:  Silicon Labs EFM32-G8xx-DK Development Kit
Device: EFM32G890F128 w/LCD only
