crypto: clarify licensing of OpenSSL asm code

Several source files have been taken from OpenSSL. In some of them a
comment that "permission to use under GPL terms is granted" was
included below a contradictory license statement. In several cases,
there was no indication that the license of the code was compatible
with the GPLv2.

This change clarifies the licensing for all of these files. I've
confirmed with the author (Andy Polyakov) that a) he has licensed the
files with the GPLv2 comment under that license and b) that he's also
happy to license the other files under GPLv2 too. In one case, the
file is already contained in his CRYPTOGAMS bundle, which has a GPLv2
option, and so no special measures are needed.

In all cases, the license status of code has been clarified by making
the GPLv2 license prominent.

The .S files have been regenerated from the updated .pl files.

This is a comment-only change. No code is changed.

Signed-off-by: Adam Langley <agl@chromium.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>