testbench: include stdlib.h

Newer GCC version complain about free() not being defined.

Signed-off-by: Liam Girdwood <liam.r.girdwood@linux.intel.com>

tools/testbench/testbench.c

@@ -16,6 +16,7 @@
 #include "testbench/trace.h"
 #include "testbench/file.h"
 #include <limits.h>
+#include <stdlib.h>
 
 #ifdef TESTBENCH_CACHE_CHECK
 #include <arch/lib/cache.h>

tools/testbench/topology.c

@@ -11,6 +11,7 @@
 #include <errno.h>
 #include <math.h>
 #include <stdio.h>
+#include <stdlib.h>
 #include <sof/common.h>
 #include <sof/string.h>
 #include <sof/audio/component.h>