Fix more hidden TSC bugs for Ericsson BTS

It seems that also the Ericsson RBS2000 code was assuming that
we always use the bts-global TSC, rather than the possibly different
TS-specific TSC.
diff --git a/openbsc/src/libbsc/abis_om2000.c b/openbsc/src/libbsc/abis_om2000.c
index d8350e5..2e5a79a 100644
--- a/openbsc/src/libbsc/abis_om2000.c
+++ b/openbsc/src/libbsc/abis_om2000.c
@@ -1203,7 +1203,7 @@
 		msgb_tv_put(msg, OM2K_DEI_NY1, 35);
 		msgb_tv_put(msg, OM2K_DEI_BA_PA_MFRMS, 0x06);
 		msgb_tv_put(msg, OM2K_DEI_CBCH_INDICATOR, 0);
-		msgb_tv_put(msg, OM2K_DEI_TSC, ts->trx->bts->tsc);
+		msgb_tv_put(msg, OM2K_DEI_TSC, gsm_ts_tsc(ts));
 		msgb_tv_put(msg, OM2K_DEI_BS_AG_BKS_RES, 0x01);
 		msgb_tv_put(msg, OM2K_DEI_ICM_INDICATOR, 0);
 		msgb_tv_put(msg, OM2K_DEI_DRX_DEV_MAX, 0x05);
@@ -1216,7 +1216,7 @@
 		msgb_tv_put(msg, OM2K_DEI_T3105, ts->trx->bts->network->T3105 / 10);
 		msgb_tv_put(msg, OM2K_DEI_NY1, 35);
 		msgb_tv_put(msg, OM2K_DEI_CBCH_INDICATOR, 0);
-		msgb_tv_put(msg, OM2K_DEI_TSC, ts->trx->bts->tsc);
+		msgb_tv_put(msg, OM2K_DEI_TSC, gsm_ts_tsc(ts));
 		/* Disable RF RESOURCE INDICATION on idle channels */
 		msgb_tv_put(msg, OM2K_DEI_ICM_INDICATOR, 0);
 		msgb_tv_fixed_put(msg, OM2K_DEI_ICM_BOUND_PARAMS,
@@ -1225,7 +1225,7 @@
 	default:
 		msgb_tv_put(msg, OM2K_DEI_T3105, ts->trx->bts->network->T3105 / 10);
 		msgb_tv_put(msg, OM2K_DEI_NY1, 35);
-		msgb_tv_put(msg, OM2K_DEI_TSC, ts->trx->bts->tsc);
+		msgb_tv_put(msg, OM2K_DEI_TSC, gsm_ts_tsc(ts));
 		/* Disable RF RESOURCE INDICATION on idle channels */
 		msgb_tv_put(msg, OM2K_DEI_ICM_INDICATOR, 0);
 		msgb_tv_fixed_put(msg, OM2K_DEI_ICM_BOUND_PARAMS,