Currently you could only invoke windeployqt for debug and release
builds, but not windeployqt_clean resulting in artifacts after
the clean step.
Change-Id: I3a93e4909a017f3594cc5b0c2249ed25b777c008
Reviewed-by: Oliver Wolff <oliver.wolff@theqtcompany.com>
Reviewed-by: Andrew Knight <qt@panimo.net>