Some hash modules load/store data words directly.  The digest layer
should pass properly aligned buffer to update()/final() method.  This
patch also add cra_alignmask to some hash modules.
Signed-off-by: NAtsushi Nemoto <anemo@mba.ocn.ne.jp>
Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>