[build] Call qdbusxml2cpp with full path

As qdbusxml2cpp can be called qdbusxml2cpp-qt5 in some systems, use Qt install bin path
to call this application

Signed-off-by: Rinigus <rinigus.git@gmail.com>

mts/platform/storage/fsstorageplugin/fsstorageplugin.pro

@@ -10,7 +10,7 @@ QT -= gui
 
 PKGCONFIG += blkid mount
 
-system(qdbusxml2cpp -c ThumbnailerProxy -p thumbnailerproxy.h:thumbnailerproxy.cpp -i thumbnailpathlist.h ./org.nemomobile.Thumbnailer.xml)
+system($$[QT_INSTALL_BINS]/qdbusxml2cpp -c ThumbnailerProxy -p thumbnailerproxy.h:thumbnailerproxy.cpp -i thumbnailpathlist.h ./org.nemomobile.Thumbnailer.xml)
 
 DEPENDPATH += . \
               .. \