Add sysname IDs for FreeBSD 10.2 and 10.3

Add sysname IDs for FreeBSD 10.2 and 10.3

While here, de-conflict the numbers for 10.0/10.1 and 7.2/7.3

Reviewed-on: https://gerrit.openafs.org/12321
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Mark Vitale <mvitale@sinenomine.net>
Reviewed-by: Benjamin Kaduk <kaduk@mit.edu>
(cherry picked from commit dda47aab6179b6940aa994a0cd7b88a4b0942fe6)

Change-Id: I434076ddd0a38ff052f977c7c0cb4feab1c533d3
Reviewed-on: https://gerrit.openafs.org/12322
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Mark Vitale <mvitale@sinenomine.net>
Reviewed-by: Michael Meffie <mmeffie@sinenomine.net>
Reviewed-by: Stephan Wiesand <stephan.wiesand@desy.de>