This adds the Linux dts files to barebox. The dts files are
generated from Ian Campbells device-tree-rebasing.git:
The dts are found in dts/ in the barebox repository and
will be updated from upstream regularly, probably for each upstream
To keep the synchronization with upstream easy no changes to
the original files are allowed under dts/. Instead changes to
upstream dts files will be done using overlays in arch/$ARCH/dts/.
Signed-off-by: Sascha Hauer <email@example.com>