drm: Add a note to drm_property_create() about property lifetime

Cc: Chandra Konduru <chandra.konduru@intel.com>
Cc: Daniel Vetter <daniel.vetter@intel.com>
Signed-off-by: NDamien Lespiau <damien.lespiau@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

drivers/gpu/drm/drm_crtc.c

@@ -3417,6 +3417,10 @@ void drm_fb_release(struct drm_file *priv)
  * object with drm_object_attach_property. The returned property object must be
  * freed with drm_property_destroy.
  *
+ * Note that the DRM core keeps a per-device list of properties and that, if
+ * drm_mode_config_cleanup() is called, it will destroy all properties created
+ * by the driver.
+ *
  * Returns:
  * A pointer to the newly created property on success, NULL on failure.
  */