drm/doc: use preferred struct reference in kernel-doc

sed -e 's/\( \* .*\)struct &\([_a-z]*\)/\1\&struct \2/' -i

Originally I wasnt a friend of this style because I thought a
line-break between the "&struct" and "foo" part would break it. But a
quick test shows that " * &struct \n * foo\n" works pefectly well with
current kernel-doc. So time to mass-apply these changes!

Cc: Jani Nikula <jani.nikula@linux.intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: David Herrmann <dh.herrmann@gmail.com>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1483044517-5770-6-git-send-email-daniel.vetter@ffwll.ch

include/drm/drm_irq.h

@@ -51,8 +51,8 @@ struct drm_pending_vblank_event {
  *
  * Note that for historical reasons - the vblank handling code is still shared
  * with legacy/non-kms drivers - this is a free-standing structure not directly
- * connected to struct &drm_crtc. But all public interface functions are taking
- * a struct &drm_crtc to hide this implementation detail.
+ * connected to &struct drm_crtc. But all public interface functions are taking
+ * a &struct drm_crtc to hide this implementation detail.
  */
 struct drm_vblank_crtc {
 	/**