I don't think so that is possible right now unless you create a custom renderer (custom skin) for the Geocoder component. The behavior comes in from the API component.
The results are shown as : {value} - {layerName} - {mapServiceName} where layername is the layer which contains the result
I have not tested this but it looks like you can find the src/com/esri/viewer/components/GeocoderComponent.mxml and find the configureMapServices function and change this line:
I don't think so that is possible right now unless you create a custom renderer (custom skin) for the Geocoder component. The behavior comes in from the API component.
The results are shown as : {value} - {layerName} - {mapServiceName} where layername is the layer which contains the result