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

drivers/gpu/drm/drm_property.c

@@ -34,7 +34,7 @@
  * even the only way to transport metadata about the desired new modeset
  * configuration from userspace to the kernel. Properties have a well-defined
  * value range, which is enforced by the drm core. See the documentation of the
- * flags member of struct &drm_property for an overview of the different
+ * flags member of &struct drm_property for an overview of the different
  * property types and ranges.
  *
  * Properties don't store the current value directly, but need to be