benchmarks: Fix build errors on Android M-Dessert

Android M-Dessert treats implicit declaration of function warnings
as errors resulting in igt failing to build.

This patch fixes the errors by including missing header files as
required. Mostly this involved including igt.h in the benchmarks.

Signed-off-by: Derek Morton <derek.j.morton@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

tools/intel_reg_decode.c

@@ -31,6 +31,7 @@
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
+#include <strings.h>
 
 #include "intel_chipset.h"
 #include "intel_reg.h"