meta-hipos: hipos time service uses UTC

The option -u is now used explicitly. Until now result of the
date command depended on the user's time zone settings.

Signed-off-by: Angelika Tobisch <tobisch@dresearch-fe.de>
meta-hipos: change script location for hipos time service

As agreed upon set-time.sh will now be put into /etc/hipos
instead of /etc/hipos/scripts

Signed-off-by: Angelika Tobisch <tobisch@dresearch-fe.de>