Build: updated hippomocks to support arm64

Build: updated hippomocks to support arm64

Without it, I will fail to build and complain about missing method.

This is latest release with this patch :
  https://github.com/dascandy/hippomocks/pull/49

It was tested on Ubuntu wily arm64, more details to be shared at :
  https://wiki.iotivity.org/community

Change-Id: Ie641ad10af4b22d191f041ad2d27ac3b998a891a
Signed-off-by: Philippe Coval <philippe.coval@osg.samsung.com>
Reviewed-on: https://gerrit.iotivity.org/gerrit/8179
Tested-by: jenkins-iotivity <jenkins-iotivity@opendaylight.org>
Reviewed-by: Ziran Sun <ziran.sun@samsung.com>
Reviewed-by: Uze Choi <uzchoi@samsung.com>