sha512: Fix new warning from incorrect range on passed array
sha512: Fix new warning from incorrect range on passed array

Reference function for sha512 had copied wrong size digest.

Change-Id: I80480f254bc2aed216a6628f8ecca6ea5741c893
Signed-off-by: Greg Tucker <190558edad8973536750c621867b946ba24dc8b8@intel.com>

intel/isa-l_crypto,intel/isa-l_crypto,intel/isa-l_crypto