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/bts_ipaccess_nanobts.c b/openbsc/src/libbsc/bts_ipaccess_nanobts.c
index dfb5a45..89d5256 100644
--- a/openbsc/src/libbsc/bts_ipaccess_nanobts.c
+++ b/openbsc/src/libbsc/bts_ipaccess_nanobts.c
@@ -369,6 +369,9 @@
 			abis_nm_opstart(trx->bts, obj_class,
 					trx->bts->bts_nr, trx->nr, ts->nr);
 		}
+		if (new_state->operational == NM_OPSTATE_ENABLED
+		    && new_state->availability == NM_AVSTATE_OK)
+			dyn_pdch_init(ts);
 		break;
 	case NM_OC_RADIO_CARRIER:
 		trx = obj;