src: use namespace prefix osmo_timer* for timer functions

Summary of changes:

s/struct timer_list/struct osmo_timer_list/g
s/bsc_add_timer/osmo_timer_add/g
s/bsc_schedule_timer/osmo_timer_schedule/g
s/bsc_del_timer/osmo_timer_del/g
s/bsc_timer_pending/osmo_timer_pending/g
s/bsc_nearest_timer/osmo_timers_nearest/g
s/bsc_prepare_timers/osmo_timers_prepare/g
s/bsc_update_timers/osmo_timers_update/g
s/bsc_timer_check/osmo_timers_check/g
diff --git a/openbsc/src/libabis/e1_input.c b/openbsc/src/libabis/e1_input.c
index 1a79261..d3a5cda 100644
--- a/openbsc/src/libabis/e1_input.c
+++ b/openbsc/src/libabis/e1_input.c
@@ -241,7 +241,7 @@
 
 	sign_link = msg->trx->rsl_link;
 	e1i_ts = sign_link->ts;
-	if (!bsc_timer_pending(&e1i_ts->sign.tx_timer)) {
+	if (!osmo_timer_pending(&e1i_ts->sign.tx_timer)) {
 		/* notify the driver we have something to write */
 		e1inp_driver = sign_link->ts->line->driver;
 		e1inp_driver->want_write(e1i_ts);
@@ -276,7 +276,7 @@
 		sign_link = msg->trx->bts->oml_link;
 
 	e1i_ts = sign_link->ts;
-	if (!bsc_timer_pending(&e1i_ts->sign.tx_timer)) {
+	if (!osmo_timer_pending(&e1i_ts->sign.tx_timer)) {
 		/* notify the driver we have something to write */
 		e1inp_driver = sign_link->ts->line->driver;
 		e1inp_driver->want_write(e1i_ts);
@@ -471,7 +471,7 @@
 	}
 
 	if (link->ts->type == E1INP_TS_TYPE_SIGN)
-		bsc_del_timer(&link->ts->sign.tx_timer);
+		osmo_timer_del(&link->ts->sign.tx_timer);
 
 	talloc_free(link);
 }