Initialise the orientation sensor at start

Summary: We want to set the right orientation as the system starts.

Reviewers: #plasma, #kwin, zzag, davidedmundson

Reviewed By: #plasma, #kwin, zzag, davidedmundson

Subscribers: zzag, kwin

Tags: #kwin

Differential Revision: https://phabricator.kde.org/D20622