dm: sunxi: dts: Add sun7i device tree files

These are from Linux 3.17-rc7 (commit fe82dcec). U-Boot only uses a small
portion of these, but we may as well have something to look forward to.

The total compiled size is about 25KB.

Acked-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>