lib: rename intel_gpu_tools.h to intel_io.h

With the header cleanup we can now give this header a suitable name,
since it now really only contains register access and other I/O
functions and assorted definitions.

Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
diff --git a/tools/intel_stepping.c b/tools/intel_stepping.c
index 626c5bb..7839ef5 100644
--- a/tools/intel_stepping.c
+++ b/tools/intel_stepping.c
@@ -32,7 +32,7 @@
 #include <pciaccess.h>
 #include <err.h>
 #include "intel_chipset.h"
-#include "intel_gpu_tools.h"
+#include "intel_io.h"
 #include "intel_reg.h"
 
 static void