dyn PDCH: send PDCH ACT for each TCH/F_PDCH on TS Enable

Add dyn_pdch_init() in new file bsc_dyn_pdch.c (new file to avoid linking
issues; bsc_init.c would create undefined references, and putting in a new file
is the easiest solution).

Call dyn_pdch_init() from nm_statechg_event() whenever a TS is enabled.

Revert the |= TS_F_PDCH_MODE chunk from previous commit, since this flag will
now be set after dyn_pdch_init() sent out the PDCH ACT and when subsequently
the PDCH ACT ACK messages are received in rsl_rx_pdch_act_ack().

Change-Id: I0cad93dec59d546b3f3b19e332e0833496031575
diff --git a/openbsc/src/libbsc/bsc_init.c b/openbsc/src/libbsc/bsc_init.c
index 04452f7..5c27862 100644
--- a/openbsc/src/libbsc/bsc_init.c
+++ b/openbsc/src/libbsc/bsc_init.c
@@ -329,10 +329,8 @@
 			llist_for_each_entry(cur_trx, &trx->bts->trx_list, list) {
 				int i;
 
-				for (i = 0; i < ARRAY_SIZE(cur_trx->ts); i++) {
+				for (i = 0; i < ARRAY_SIZE(cur_trx->ts); i++)
 					generate_ma_for_ts(&cur_trx->ts[i]);
-					cur_trx->ts[i].flags |= TS_F_PDCH_MODE;
-				}
 			}
 		}
 		if (isd->link_type == E1INP_SIGN_RSL)