Remove usage of external dependencies from the RSS News demo

Examples in qtdeclarative shouldn't depend on Qt Quick Controls,
Layouts, or add on modules like Qt Graphical Effects.

Change-Id: Ic069ed3223a4cfebde5263e846ae394aebed0b33
Reviewed-by: Jerome Pasion <jerome.pasion@digia.com>
Reviewed-by: Leena Miettinen <riitta-leena.miettinen@digia.com>
Reviewed-by: Niels Weber <niels.weber@digia.com>