Added missing include to fix build.
Added missing include to fix build.

Fixes build after change in qtbase requiring Q_DECLARE_METATYPE(T*) to
be fully defined.

Change-Id: I741d91eb0e7e480b5a35a4616b32a90043f01a63
Sanity-Review: Qt Sanity Bot <5581206bb7e0307f0d99eb71898ae6b694149ca5@ovi.com>
Reviewed-by: Stephen Kelly <b039a7232b458ac8785f8e91519ad165c3ac28cd@kdab.com>

locusf/qtwayland-1,locusf/qtwayland-1,Tofee/qtwayland,ntanibata/qtwayland,ntanibata/qtwayland,Tofee/qtwayland,locusf/qtwayland-1,Tofee/qtwayland,ntanibata/qtwayland,locusf/qtwayland-1