Move control_ts explicit checks out of the scheduler implementation

Let each subsystem handle that internally.

Change-Id: Ifaf7dde651d56942779d84aa9135fc8c974b6f26
diff --git a/src/nacc_fsm.c b/src/nacc_fsm.c
index 25e7cd8..b4d8583 100644
--- a/src/nacc_fsm.c
+++ b/src/nacc_fsm.c
@@ -900,3 +900,11 @@
 	       ctx->continue_poll_fn == fn &&
 	       ctx->continue_poll_ts == ts;
 }
+
+bool tbf_nacc_rts(const struct gprs_rlcmac_tbf *tbf, const struct gprs_rlcmac_pdch *pdch)
+{
+	if (!tbf_is_control_ts(tbf, pdch))
+		return false;
+
+	return tbf_is_tfi_assigned(tbf) && ms_nacc_rts(tbf_ms(tbf));
+}