Revert "doc: update Kernel documentation build system"

Unfortunately we now see a number of now-fatal warnings about duplicate
labels.  It is often unclear how best to re-write the document in
question to not duplicate these otherwise logical headings.

This reverts commit 10a1df3cd4.

Signed-off-by: Tom Rini <trini@konsulko.com>

doc/sphinx/kernellog.py

@@ -25,8 +25,4 @@ def verbose(app, message):
     else:
         app.verbose(message)
 
-def info(app, message):
-    if UseLogging:
-        logger.info(message)
-    else:
-        app.info(message)
+