Added an own debug-print option for timers.c (used TCPIP_DEBUG and SYS_DEBUG as the code was copied from there)

src/include/lwip/opt.h

@@ -1804,6 +1804,13 @@
 #define SYS_DEBUG                       LWIP_DBG_OFF
 #endif
 
+/**
+ * TIMERS_DEBUG: Enable debugging in timers.c.
+ */
+#ifndef TIMERS_DEBUG
+#define TIMERS_DEBUG                    LWIP_DBG_OFF
+#endif
+
 /**
  * TCP_DEBUG: Enable debugging for TCP.
  */