drm/of: Fix kerneldoc

I noticed a link that didn't work ...

Fixes: 1f2db3034c9f ("drm: of: introduce drm_of_find_panel_or_bridge")
Cc: Rob Herring <[e-mail]>
Cc: Philipp Zabel <[e-mail]>
Cc: Sean Paul <[e-mail]>
Reviewed-by: Sam Ravnborg <[e-mail]>
Signed-off-by: Daniel Vetter <[e-mail]>
Link: https://patchwork.freedesktop.org/patch/msgid/[e-mail]

drivers/gpu/drm/drm_of.c

···
 }
 EXPORT_SYMBOL_GPL(drm_of_encoder_active_endpoint);
 
-/*
+/**
  * drm_of_find_panel_or_bridge - return connected panel or bridge device
  * @np: device tree node containing encoder output ports
+ * @port: port in the device tree node
+ * @endpoint: endpoint in the device tree node
  * @panel: pointer to hold returned drm_panel
  * @bridge: pointer to hold returned drm_bridge
  *