Add an icon for Thunderbolt KCM
Summary: An icon for D19011
Test Plan:
PNG version:
Reviewers: VDG, ndavis, ngraham
Reviewed By: VDG, ndavis, ngraham
Subscribers: abetts, ndavis, GB_2, filipf, ngraham, kde-frameworks-devel
Tags: Frameworks
Differential Revision: https://phabricator.kde.org/D20672