drm/panel: Flesh out kerneldoc

Write more complete kerneldoc comments for the DRM panel API and
integrate the helpers in the DRM DocBook reference.

Signed-off-by: Thierry Reding <treding@nvidia.com>drm/panel: Add helper for simple panel connector
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/20160506140137.GA4641@ulmo.ba.sec
diff --git a/Documentation/DocBook/gpu.tmpl b/Documentation/DocBook/gpu.tmpl
index 56386d3..9dd48f7 100644
--- a/Documentation/DocBook/gpu.tmpl
+++ b/Documentation/DocBook/gpu.tmpl
@@ -1671,17 +1671,23 @@
 !Pdrivers/gpu/drm/drm_crtc.c Tile group
     </sect2>
     <sect2>
-	<title>Bridges</title>
+      <title>Bridges</title>
       <sect3>
-	 <title>Overview</title>
+        <title>Overview</title>
 !Pdrivers/gpu/drm/drm_bridge.c overview
       </sect3>
       <sect3>
-	 <title>Default bridge callback sequence</title>
+        <title>Default bridge callback sequence</title>
 !Pdrivers/gpu/drm/drm_bridge.c bridge callbacks
       </sect3>
 !Edrivers/gpu/drm/drm_bridge.c
     </sect2>
+    <sect2>
+      <title>Panel Helper Reference</title>
+!Iinclude/drm/drm_panel.h
+!Edrivers/gpu/drm/drm_panel.c
+!Pdrivers/gpu/drm/drm_panel.c drm panel
+    </sect2>
   </sect1>
 
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