qt5: bump to 5.0.2

A new version of Qt5 has been released, 5.0.2, so let's use it, see
http://blog.qt.digia.com/blog/2013/04/10/qt-5-0-2-released/

: "Qt 5.0.2
brings over 600 improvements compared to Qt 5.0.1, most of these in
order to address the issues Qt users have noted when bringing their
applications to Qt 5.".

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: Peter Korsgaard <jacmet@sunsite.dk>