jhash: restore the old version of hash for serial number generation

jhash: restore the old version of hash for serial number generation

BZ: 21473

having a different serial number for R2 and R3 is too annoying for people,
so we use the old version of the algorithm

This new file will only be included by android.c thus do not
impact any other user of jhash

Change-Id: I5ea9493de9380584a27cb128d042f5e32e0ab52f
Signed-off-by: Pierre Tardy <pierre.tardy@intel.com>
Reviewed-on: http://android.intel.com:8080/33094
Reviewed-by: buildbot <buildbot@intel.com>
Tested-by: buildbot <buildbot@intel.com>