drm/i915/selftests: Include <linux/prandom.h> instead of <linux/random.h>

Substitute the inclusion of <linux/random.h> header with
<linux/prandom.h> to allow the removal of legacy inclusion
of <linux/prandom.h> from <linux/random.h>.

Signed-off-by: Uros Bizjak <[e-mail]>
Cc: Joonas Lahtinen <[e-mail]>
Cc: Rodrigo Vivi <[e-mail]>
Cc: Tvrtko Ursulin <[e-mail]>
Cc: David Airlie <[e-mail]>
Cc: Daniel Vetter <[e-mail]>
Acked-by: Jani Nikula <[e-mail]>
Signed-off-by: Jason A. Donenfeld <[e-mail]>

drivers/gpu/drm/i915/selftests/i915_gem.c

···
  * Copyright © 2018 Intel Corporation
  */
 
-#include <linux/random.h>
+#include <linux/prandom.h>
 
 #include "gem/i915_gem_internal.h"
 #include "gem/i915_gem_pm.h"

drivers/gpu/drm/i915/selftests/i915_random.h

···
 #define __I915_SELFTESTS_RANDOM_H__
 
 #include <linux/math64.h>
-#include <linux/random.h>
+#include <linux/prandom.h>
 
 #include "../i915_selftest.h"
 

drivers/gpu/drm/i915/selftests/scatterlist.c

···
  */
 
 #include <linux/prime_numbers.h>
-#include <linux/random.h>
+#include <linux/prandom.h>
 
 #include "i915_selftest.h"
 #include "i915_utils.h"