s390x: Fix the confusing contributions-after-2012 license statements

s390x: Fix the confusing contributions-after-2012 license statements

The license information in these files is rather confusing. The text
declares LGPL first, but then says that contributions after 2012 are
licensed under the GPL instead. How should the average user who just
downloaded the release tarball know which part is now GPL and which
is LGPL?

Looking at the text of the LGPL (see COPYING.LIB in the top directory),
the license clearly states how this should be done instead:

"3. You may opt to apply the terms of the ordinary GNU General Public
 License instead of this License to a given copy of the Library. To do
 this, you must alter all the notices that refer to this License, so
 that they refer to the ordinary GNU General Public License, version 2,
 instead of to this License."

Thus let's clean up the confusing statements and use the proper GPL
text only.

Signed-off-by: Thomas Huth <thuth@redhat.com>
Message-Id: <1549456893-16589-1-git-send-email-thuth@redhat.com>
Acked-by: Laurent Vivier <laurent@vivier.eu>
Acked-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Cornelia Huck <cohuck@redhat.com>