OM2000: Add some more message types and IEs we now understand

OM2000 is not only used for the venerable RBS2000 family, but also
for the more modern RBS6000 family, specifically the DUG 20 GSM
baseband unit.

In RBS6000, there are some protocol extensions which are not yet fully
understood. However, we are understanding some bits around the MCTR
(multi carrier transceiver?), a new MO that appears to be present for
every physical RUS (Radio Unit) attached to the DUG 20.

Let's add what we have learned so far.

Thanks to Sylvain Munaut for his help with this.

Change-Id: Ib868358eca12b94c4fcca58e94ec8ab1a4edfda2
2 files changed