bsc-sccplite CBSP: fix osmo-bsc.cfg to contain 3 BTS with a CBCH
Fix the TC_si2quater_* test fallout.
When adjusting the bsc AoIP test config, forgot to also adjust the SCCPlite
test suite config, which caused fallout in the SCCPlite tests.
Related: Idbcc703ace7012fb395f0eef3e445df28b368d74 (docker-playground)
Related: Iac46ee2cc5bc0978d5f5baa550baf493a7c56b1b (osmo-ttcn3-hacks)
Change-Id: I810ff6f89d722e7274046c360a2cbebf6f6ee53a
