lib: extract igt_aux.[hc]

And shovel all the various helpers in there.

Also move igt_set_vt_graphics_mode to igt_kms.h since the function is
implemented in igt_kms.c. And it fits better. I kinda missed this in
the prep work.

Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

tests/gem_partial_pwrite_pread.c

@@ -33,13 +33,14 @@
 #include <errno.h>
 #include <sys/stat.h>
 #include <sys/time.h>
-#include "drm.h"
+
+#include <drm.h>
+
 #include "ioctl_wrappers.h"
 #include "drmtest.h"
 #include "intel_chipset.h"
-#include "intel_bufmgr.h"
-#include "intel_batchbuffer.h"
 #include "intel_io.h"
+#include "igt_aux.h"
 
 /*
  * Testcase: pwrite/pread consistency when touching partial cachelines