drm/mode: document path property and function to set it. (v1.1)

These two didn't get documented properly, do so.

Pointed out by Daniel.

v1.1: add missing boilerplate (Daniel)

Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Dave Airlie <airlied@redhat.com>
2 files changed