Re-add HAL policy file to disable hald-addon-hid-ups

While NUT has removed its HAL support (see issue #99), a policy file is still needed to run NUT in non-HAL mode on a platform with HAL.

Reference: http://lists.alioth.debian.org/pipermail/nut-upsuser/2016-November/010418.html

CentOS 6.8 will be supported for another four years, so if anyone wants to backport a current version of NUT during that time, they will need this.