Simplifies the way of building dbus-cynara by removing
the specific recipes in favour of a recipe for dbus that
handles the class-target build feature.
It requires to remove fake dependencies of cynara.
This is a suggestion of Tom Rini.
Bug-AGL: SPEC-1839
Change-Id: Id7a736eb4b73cdb679fa9dde30e9ad8e56c2894e Signed-off-by: José Bollo <jose.bollo@iot.bzh>