Add axis support to zoom effect

Using Ctrl+Meta+Wheel as Meta+Wheel is already used by Weston for this
feature, so it would not be possible to test it.

effects/zoom/zoom.cpp

@@ -68,11 +68,13 @@ ZoomEffect::ZoomEffect()
     KGlobalAccel::self()->setDefaultShortcut(a, QList<QKeySequence>() << Qt::META + Qt::Key_Equal);
     KGlobalAccel::self()->setShortcut(a, QList<QKeySequence>() << Qt::META + Qt::Key_Equal);
     effects->registerGlobalShortcut(Qt::META + Qt::Key_Equal, a);
+    effects->registerAxisShortcut(Qt::ControlModifier | Qt::MetaModifier, PointerAxisDown, a);
 
     a = KStandardAction::zoomOut(this, SLOT(zoomOut()), this);
     KGlobalAccel::self()->setDefaultShortcut(a, QList<QKeySequence>() << Qt::META + Qt::Key_Minus);
     KGlobalAccel::self()->setShortcut(a, QList<QKeySequence>() << Qt::META + Qt::Key_Minus);
     effects->registerGlobalShortcut(Qt::META + Qt::Key_Minus, a);
+    effects->registerAxisShortcut(Qt::ControlModifier | Qt::MetaModifier, PointerAxisUp, a);
 
     a = KStandardAction::actualSize(this, SLOT(actualSize()), this);
     KGlobalAccel::self()->setDefaultShortcut(a, QList<QKeySequence>() << Qt::META + Qt::Key_0);