HO: Count number of free timeslot on a given BTS

This is needed for handover algorithm to balance free slots and to prevent
congestion of one cell, while other cells still have free capacities.

Change-Id: Ic8bee8a515ee8aa9a99af71756fe60b8dd8f868b
diff --git a/include/osmocom/bsc/chan_alloc.h b/include/osmocom/bsc/chan_alloc.h
index f2a75c5..748e9cd 100644
--- a/include/osmocom/bsc/chan_alloc.h
+++ b/include/osmocom/bsc/chan_alloc.h
@@ -24,6 +24,9 @@
 
 struct gsm_subscriber_connection;
 
+/* Count number of free TS of given pchan type */
+int bts_count_free_ts(struct gsm_bts *bts, enum gsm_phys_chan_config pchan);
+
 /* Allocate a logical channel (SDCCH, TCH, ...) */
 struct gsm_lchan *lchan_alloc(struct gsm_bts *bts, enum gsm_chan_t type, int allow_bigger);