Bump module version to 5.4.0

Change-Id: I6bf5c8d40b53a25f761c0638d7a08c20557ecead
Reviewed-by: Sergio Ahumada <sahumada@blackberry.com>
Reviewed-by: Lars Knoll <lars.knoll@digia.com>
Reviewed-by: Laszlo Papp <lpapp@kde.org>