InputRouter channel assignment (eliminate magic constants)

[tschuh]

TO DO: Eliminate cfg param IRChannelsIn from https://github.com/cms-sw/cmssw/blob/master/L1Trigger/TrackFindingTracklet/python/Customize_cff.py#L22 by taking this info from Tracklet wiring map.
e.g. The list above "0, 1, 25," indicates that 2nd IR module (where counting starts at 0) is connected to DTC ID = 25. And LUTsReduced/processingmodules.dat says that2nd IR is named IR_PS10G_2_B , which wires.dat says is connected to the DTC named DL_PS10G_2_B . And using array dtcname (from L1FPGATrackProducer.cc), one finds that "PS10G_2" is in slot 1 of the crate, and this name also means its at +ve z and in the 2nd Tracker sector connected to this TFP region. From this info, a function added to your Setup class should be able to return the DTC ID. The difficulty is that EDProducer ChannelAssignment accesses IRChannelsIn, but doesn't have access to the wiring map.