Internal temperature sensor example.

This example project uses the EFM32 CMSIS and emlib to demonstrate
the usage of the internal temperature sensor on EFM32 Leopard Gecko
devices.

Note: EFM32 devices with production ID lower than 18 may measure inaccurate
temperatures due to a sensor calibration bug.

Board:  Silicon Labs EFM32LG_STK3600 Starter Kit
Device: EFM32LG990F256

