board: Add support for Acmesystems Arietta g25

This patch adds a minimal working configuration for
Acmesystems Arietta g25.

[Peter: fix whitespace, use same-as-kernel for kernel headers version]
Signed-off-by: Angelo Compagnucci <angelo.compagnucci@gmail.com>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>
5 files changed