drm/i915: change i915_sw_fence license to MIT

Change the license of the i915_sw_fence files to MIT matching
most of the other i915 files.  This makes it possible to use them
in a new port of i915 to OpenBSD.

Besides some mechanical tree wide changes Chris Wilson is the sole
author of these files with Intel holding the copyright.

Intel's legal team have given permission to change the license according
to Joonas Lahtinen.

v2: expand commit message and note permission from Intel legal
Signed-off-by: Jonathan Gray <jsg@jsg.id.au>
Cc: Jani Nikula <jani.nikula@linux.intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20181129013051.17525-1-jsg@jsg.id.au

drivers/gpu/drm/i915/i915_sw_fence.c

 /*
- * (C) Copyright 2016 Intel Corporation
+ * SPDX-License-Identifier: MIT
  *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public License
- * as published by the Free Software Foundation; version 2
- * of the License.
+ * (C) Copyright 2016 Intel Corporation
  */
 
 #include <linux/slab.h>

drivers/gpu/drm/i915/i915_sw_fence.h

 /*
+ * SPDX-License-Identifier: MIT
+ *
  * i915_sw_fence.h - library routines for N:M synchronisation points
  *
  * Copyright (C) 2016 Intel Corporation
- *
- * This file is released under the GPLv2.
- *
  */
 
 #ifndef _I915_SW_FENCE_H_