Lightsensor example using LESENSE.

This example project uses the EFM32 CMSIS and demonstrates the use of 
the LESENSE peripheral on the board.

This demo has two different modes.
To change between them, press PB0. In Mode0 (default). The LESENSE
module will wake up whenever a "dark" event is detected by the light sensor
below the "EFM32" sign on the right from the LCD on the STK. In Mode 1, 
EFM32 will only wake up on every fifth "dark" event.

Board: Silicon Labs EFM32TG_STK3300 Development Kit
Device: EFM32TG840F32
