xtimer: Remove old xtimer_trace.h include

The file was missing anyway.

xtimer: Remove old xtimer_trace.h include
e4e18146 · Joakim Nohlgård · 6768ae9c · e4e18146
Commit e4e18146 authored 8 years ago by Joakim Nohlgård
--- a/sys/include/xtimer/implementation.h
+++ b/sys/include/xtimer/implementation.h
@@ -25,13 +25,6 @@

 #include "periph/timer.h"

-/**
- * @brief internal define to allow using variables instead of defines
- */
-#ifdef XTIMER_TRACE
-#include "xtimer_trace.h"
-#endif
-
 #ifdef __cplusplus
 extern "C" {
 #endif