Replace QStyleOptionViewItemV? with QStyleOptionViewItem

Replace QStyleOptionViewItemV? with QStyleOptionViewItem

The former are a typedef for the latter in Qt 5. This only touches
internal implementation, as the API was migrated long ago.

Change-Id: Ided73021ebecc00508e6325c3d988b6c6ad336cd
Reviewed-by: Marc Mutz <marc.mutz@kdab.com>
Reviewed-by: Jens Bache-Wiig <jens.bache-wiig@digia.com>
Reviewed-by: Stephen Kelly <stephen.kelly@kdab.com>