ComboBox: Fix popup position on Mac
ComboBox: Fix popup position on Mac

Change-Id: I2e3ee5f812df1993220917a1cf754a852217105c
Reviewed-by: Jens Bache-Wiig <9cea9d70b08f8210134ec5959114f72bad51ed1d@digia.com>

richardmg/qtcomponents,drgvond/qtquickcontrols,richardmg/qtcomponents,mizukusak/qtquickcontrols,jfaust/qtquickcontrols,jfaust/qtquickcontrols,drgvond/qtquickcontrols,richardmg/qtcomponents,kobolabs/qtquickcontrols,kobolabs/qtquickcontrols,kobolabs/qtquickcontrols,mizukusak/qtquickcontrols,jfaust/qtquickcontrols,mizukusak/qtquickcontrols,drgvond/qtquickcontrols