Doc: Updated url variable in qdocconf files.

In 5.2, the HTML output is in a flatter structure and when they are
hosted in qt-project.org/doc, the documentation will be found at
http://qt-project.org/doc/qt-$QT_VER



The url variable is used by projects outside of Qt 5 which need
to link to Qt 5 documentation, such as Qt Creator.

Task-number: QTBUG-34584
Change-Id: Ifb9ba5c4a0e78b6170c448ec97f0bec8fa80bdfe
Reviewed-by: J-P Nurmi <jpnurmi@digia.com>
Reviewed-by: Jerome Pasion <jerome.pasion@digia.com>

src/controls/doc/qtquickcontrols.qdocconf

@@ -2,7 +2,7 @@ include($QT_INSTALL_DOCS/global/qt-module-defaults.qdocconf)
 
 project                 = QtQuickControls
 description             = Qt Quick Controls Reference Documentation
-url                     = http://qt-project.org/doc/qt-$QT_VER/qtquickcontrols/
+url                     = http://qt-project.org/doc/qt-$QT_VER
 version                 = $QT_VERSION
 
 qhp.projects            = QtQuickControls

src/layouts/doc/qtquicklayouts.qdocconf

@@ -2,7 +2,7 @@ include($QT_INSTALL_DOCS/global/qt-module-defaults.qdocconf)
 
 project                 = QtQuickLayouts
 description             = Qt Quick Layouts Reference Documentation
-url                     = http://qt-project.org/doc/qt-$QT_VER/qtquicklayouts/
+url                     = http://qt-project.org/doc/qt-$QT_VER
 version                 = $QT_VERSION
 
 qhp.projects            = QtQuickLayouts