[RBS2000] Actually activate the RBS2000 support

The previous patch introduces new code for the RBS2000 but didn't
actually activate/call it yet.

After this patch, you can see LAPD being established and OM2000 messages
will fall into abis_nm.c (which of course has no clue about them).
diff --git a/openbsc/src/bts_ericsson_rbs2000.c b/openbsc/src/bts_ericsson_rbs2000.c
index a0b5d97..484dba6 100644
--- a/openbsc/src/bts_ericsson_rbs2000.c
+++ b/openbsc/src/bts_ericsson_rbs2000.c
@@ -77,7 +77,7 @@
 {
 	struct e1inp_ts *e1i_ts = _line;
 
-	lapd_transmit_sabm(e1i_ts->driver.dahdi.lapd, 62, 62);
+	lapd_send_sabm(e1i_ts->driver.dahdi.lapd, 62, 62);
 
 	bsc_schedule_timer(&sabm_timer, 0, 50);
 }
@@ -93,12 +93,14 @@
 
 	switch (signal) {
 	case S_INP_TEI_UP:
+		bsc_del_timer(&sabm_timer);
 		switch (isd->link_type) {
 		case E1INP_SIGN_OML:
 			if (isd->trx->bts->type == GSM_BTS_TYPE_BS11)
 				bootstrap_om_rbs2k(isd->trx->bts);
 			break;
 		}
+		break;
 	case S_INP_LINE_INIT:
 		/* Right now Ericsson RBS are only supported on DAHDI */
 		if (strcasecmp(isd->line->driver->name, "DAHDI"))