don't glob everything and the kitchen sink
Summary:
we have two themes. glob the two themes and nothing else.
otherwise when keeping the build directory in ./build/ we'd glob that too
which may take ages and is entirely useless.
Test Plan: cmake .. && make && cmake .. doesn't take a million years
Reviewers: Breeze, VDG, ngraham
Reviewed By: Breeze, VDG, ngraham
Subscribers: kde-frameworks-devel
Tags: Frameworks
Differential Revision: https://phabricator.kde.org/D21100