llc: Count timedout and silently dropped frames

A DL tbf can be discarded and then the already queued LLCs will
be silently dropped. Count this event.
diff --git a/src/bts.h b/src/bts.h
index 3ffd219..259be20 100644
--- a/src/bts.h
+++ b/src/bts.h
@@ -157,6 +157,8 @@
 		CTR_SBA_ALLOCATED,
 		CTR_SBA_FREED,
 		CTR_SBA_TIMEDOUT,
+		CTR_LLC_FRAME_TIMEDOUT,
+		CTR_LLC_FRAME_DROPPED,
 	};
 
 	BTS();
@@ -198,6 +200,8 @@
 	void sba_allocated();
 	void sba_freed();
 	void sba_timedout();
+	void timedout_frame();
+	void dropped_frame();
 
 	/*
 	 * Below for C interface for the VTY
@@ -256,6 +260,8 @@
 CREATE_COUNT_INLINE(sba_allocated, CTR_SBA_ALLOCATED)
 CREATE_COUNT_INLINE(sba_freed, CTR_SBA_FREED)
 CREATE_COUNT_INLINE(sba_timedout, CTR_SBA_TIMEDOUT)
+CREATE_COUNT_INLINE(timedout_frame, CTR_LLC_FRAME_TIMEDOUT);
+CREATE_COUNT_INLINE(dropped_frame, CTR_LLC_FRAME_DROPPED);
 
 #undef CREATE_COUNT_INLINE