Receive cell informations via PCU socket interface

These informations provide RAI, timers, counters and other attributes to
the BSSGP and RLC/MAC processes.

The attributes are stored in gprs_rlcmac_bts global structure.
diff --git a/src/pcu_main.cpp b/src/pcu_main.cpp
index 08c75cc..ae176bc 100644
--- a/src/pcu_main.cpp
+++ b/src/pcu_main.cpp
@@ -58,7 +58,7 @@
 	gprs_rlcmac_bts = talloc_zero(NULL, struct gprs_rlcmac_bts);
 	if (!gprs_rlcmac_bts)
 		return -ENOMEM;
-	gprs_rlcmac_bts->cs = 1;
+	gprs_rlcmac_bts->initial_cs = 1;
 
 	osmo_init_logging(&gprs_log_info);
 	pcu_l1if_open();