A backward compatible update for the balenaFin carrier board for the
Raspberry Pi Compute Module 3/3+ Lite.

The updated overlay includes:
  * support for the newly introduced RGB LEDs
  * i2c-gpio and SDIO improvements
  * DT based Marvell 88W8887 configuration

Signed-off-by: Zahari Petkov <zahari@balena.io>