Re: libfdt: Correctly handle versions > 17

So, like, the other day David Gibson mumbled:

If future dtb version > 17 are defined, that are still backwards
compatible with v16, libfdt will of course be able to read and
understand them.  However, when modifying such a tree, it can't
guarantee that it won't clobber additional structure from the new
version which it doesn't know about.  Therefore, before making
modifications to a tree of version >17, we must change it's version to
be exactly 17.

Signed-off-by: David Gibson <redacted>

Applied.

jdl