mme: Parametrize RAI+CI used by emulated SGSN

This will be used further in subsequent tests, plus it is configured in
the sgsn peer list of open5gs-mmed.cfg, so it knows how to route/find
SGSN peers.

Change-Id: Ia7d807bb5d75d711be7d4f6fbccd8fd123da171f
1 file changed