Add readout mapping on dynap-network 'make_config' method for Speck2e/f

[ssinhaleite]

Currently, we have to make mapping by restructuring the last linear layer of the model before implementing the dynap-network for speck2e and 2f device. I think we could integrate this work into make_config method which takes arguments including "device"?

[sheiksadique]

Currently this behaviour is accomplished by remapping the model using the method sinabs.backend.dynapcnn.utils.extend_readout_layer() manually/explicitly. Automating this behaviour might mean the users see unexpected behaviour ie. the channel numbers of the events read might not match the conceptual channel numbers.