The dtc tree currently includes two copies of the GPL - one which was
there originally, and one imported from the libfdt tree. This patch
gets rid of the extra copy in the libfdt tree.
In addition it renames the file containing the remaining copy from
COPYING to GPL. Since libfdt is dual-licensed, this seems clearer.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>