s390x assembly pack: allow alignment hints for vector load/store
s390x assembly pack: allow alignment hints for vector load/store

z14 introduced alignment hints to help vector load/store
performance. For its predecessors, alignment hint defaults
to 0 (no alignment indicated).

Signed-off-by: Patrick Steuer <patrick.steuer@de.ibm.com>

Reviewed-by: Paul Dale <bc4a6b4cd7a8395c734c8eb5aef04a9c30188c85@oracle.com>
Reviewed-by: Richard Levitte <5fb523282dd7956571c80524edc2dccfa0bd8234@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/8181)

openssl/openssl,openssl/openssl,openssl/openssl,openssl/openssl,openssl/openssl,openssl/openssl