Doc: Add SplitView to the ingroup views

Change-Id: Ifa95b8db73b78c3b46d7d18bc55aa06d2569c89e
Reviewed-by: J-P Nurmi <jpnurmi@digia.com>

src/controls/SplitView.qml

@@ -46,6 +46,7 @@ import QtQuick.Controls.Private 1.0 as Private
 /*!
     \qmltype SplitView
     \inqmlmodule QtQuick.Controls 1.0
+    \ingroup views
     \brief SplitView is a component that lays out items horizontally or
     vertically with a draggable splitter between each item.