The only real 1-1 relationship between BTS NM objects is the one between
GPRS Cell and BTS (which is actually a BTS cell).
In our current osmo-bts implementation we don't care much since we only
handle 1-cell BTSses, but let's make the data structure organization
more generic.
Implementation notes:
The gsm_bts_sm is moved to its own file, APIs to allocate are added and
the new public object is hooked correctly in the allocation process of
osmo-bsc.
Change-Id: I06461b7784fa2a78de37383406e35beae85fbad8
Alexander Couzens
Pau Espin