dtc: Convert "name" property checking to new infrastructure

[Jon Loeliger]

So, like, the other day David Gibson mumbled:
> This patch removes the old-style checking code for the "name" property
> - i.e. verifying that the "name" property, if present, matches the
> node name.  It replaces it with a pair of more-or-less equivalent
> checks in the new checking framework.
> 
> This also promotes this check to a "structural" check, or at least an
> error-rather-than-warning test, since the structural/semantic
> distinction doesn't really apply in the new framework.
> 
> A testcase for the check is also added.
> 
> Signed-off-by: David Gibson <david at gibson.dropbear.id.au>

Applied.

jdl