Move LLC enqueuing and retransmit timer to MS object

The LLC queue is already in the MS object. The LLC timer and most
of the logic to enqueue its data is independent from the TBF.

Change-Id: I56b89fcac838d8eb732b629734d5e458e9c806d1
diff --git a/src/tbf.h b/src/tbf.h
index 31bbe5f..b34476e 100644
--- a/src/tbf.h
+++ b/src/tbf.h
@@ -148,6 +148,7 @@
 bool tbf_is_control_ts(const struct gprs_rlcmac_tbf *tbf, uint8_t ts);
 bool tbf_can_upgrade_to_multislot(const struct gprs_rlcmac_tbf *tbf);
 int tbf_update(struct gprs_rlcmac_tbf *tbf);
+int tbf_establish_dl_tbf_on_pacch(struct gprs_rlcmac_tbf *tbf);
 #ifdef __cplusplus
 }
 #endif