dyn TS: split dyn_pdch_init() for new dyn type and rename

Init both TCH/F_PDCH and TCH/F_TCH/H_PDCH via dyn_ts_init(), which
refactors dyn_pdch_init().

Make dyn_ts_switchover_start from abis_rsl.c public in abis_rsl.h, so we can
start the initial switchover to PDCH from dyn_ts_init(); in abis_rsl.h include
gsm_utils.h for enum gsm_phys_chan_config.

Change-Id: I5c0b257ba8ff0e9c9a2268681a84b0681a778368
diff --git a/openbsc/src/libbsc/bts_ipaccess_nanobts.c b/openbsc/src/libbsc/bts_ipaccess_nanobts.c
index 89d5256..a6c8e29 100644
--- a/openbsc/src/libbsc/bts_ipaccess_nanobts.c
+++ b/openbsc/src/libbsc/bts_ipaccess_nanobts.c
@@ -371,7 +371,7 @@
 		}
 		if (new_state->operational == NM_OPSTATE_ENABLED
 		    && new_state->availability == NM_AVSTATE_OK)
-			dyn_pdch_init(ts);
+			dyn_ts_init(ts);
 		break;
 	case NM_OC_RADIO_CARRIER:
 		trx = obj;