cbsp: Add enum and value string for Cause

Change-Id: I35592bb4fff2e7b442d0e0cd537b66687862baf2
diff --git a/TODO-RELEASE b/TODO-RELEASE
index 9f9f9d9..5f9d6e8 100644
--- a/TODO-RELEASE
+++ b/TODO-RELEASE
@@ -12,3 +12,4 @@
 libosmogb	ABI BREAKAGE		Add reset_ack_notification function pointer to struct bssgp_bvc_fsm_ops
 libosmogsm      add API                 Add rach_tx_integer_raw2val() in gsm_utils.h
 libosmogsm      add API                 iuup.h
+libosmogsm      add API                 cbsp.h enum osmo_cbsp_cause, osmo_cbsp_cause_name(s)