Unify BTS into a C usable structure

Previous work on BTS class started to get stuff out of the C++ struct
 into a C struct (BTS -> struct gprs_glcmac_bts) so that some parts of
it were accessible from C code. Doing so, however, ended up being messy
too, since all code needs to be switching from one object to another,
which actually refer to the same logical component.

Let's instead rejoin the structures and make sure the struct is
accessible and usable from both C and C++ code by rewriting all methods
to be C compatible and converting 3 allocated suboject as pointers.
This way BTS can internally still use those C++ objects while providing
a clean APi to both C and C++ code.

Change-Id: I7d12c896c5ded659ca9d3bff4cf3a3fc857db9dd
diff --git a/src/gprs_pcu.c b/src/gprs_pcu.c
index bc9b350..b280652 100644
--- a/src/gprs_pcu.c
+++ b/src/gprs_pcu.c
@@ -109,8 +109,7 @@
 	the_pcu->vty.initial_cs_ul = cs_ul;
 
 	/*TODO: once we support multiple bts, foreach(bts) apply */
-	struct gprs_rlcmac_bts *bts = bts_data(pcu->bts);
-	bts_recalc_initial_cs(bts);
+	bts_recalc_initial_cs(pcu->bts);
 }
 void gprs_pcu_set_initial_mcs(struct gprs_pcu *pcu, uint8_t mcs_dl, uint8_t mcs_ul)
 {
@@ -118,8 +117,7 @@
 	the_pcu->vty.initial_mcs_ul = mcs_ul;
 
 	/*TODO: once we support multiple bts, foreach(bts) apply */
-	struct gprs_rlcmac_bts *bts = bts_data(pcu->bts);
-	bts_recalc_initial_mcs(bts);
+	bts_recalc_initial_mcs(pcu->bts);
 }
 
 void gprs_pcu_set_max_cs(struct gprs_pcu *pcu, uint8_t cs_dl, uint8_t cs_ul)
@@ -127,14 +125,12 @@
 	the_pcu->vty.max_cs_dl = cs_dl;
 	the_pcu->vty.max_cs_ul = cs_ul;
 	/*TODO: once we support multiple bts, foreach(bts) apply */
-	struct gprs_rlcmac_bts *bts = bts_data(pcu->bts);
-	bts_recalc_max_cs(bts);
+	bts_recalc_max_cs(pcu->bts);
 }
 void gprs_pcu_set_max_mcs(struct gprs_pcu *pcu, uint8_t mcs_dl, uint8_t mcs_ul)
 {
 	the_pcu->vty.max_mcs_dl = mcs_dl;
 	the_pcu->vty.max_mcs_ul = mcs_ul;
 	/* TODO: once we support multiple bts, foreach(bts) apply */
-	struct gprs_rlcmac_bts *bts = bts_data(pcu->bts);
-	bts_recalc_max_mcs(bts);
+	bts_recalc_max_mcs(pcu->bts);
 }