Restructure sources

Move hardware-spicefic files into subdirectory similar to the way it's
done in OsmoBTS to make adding new hardware support easier.

Change-Id: I05004ad9032759a5dbfa57290ed1df83e89d5cb8
Related: SYS#2443
Reviewed-on: https://gerrit.osmocom.org/58
Tested-by: Jenkins Builder
Reviewed-by: Holger Freyther <holger@freyther.de>
7 files changed