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>

lib/intel_os.c

@@ -48,8 +48,8 @@
 #endif
 
 #include "intel_io.h"
-#include "i915_drm.h"
 #include "drmtest.h"
+#include "igt_aux.h"
 
 uint64_t
 intel_get_total_ram_mb(void)