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