kernel-labs: Mention attendees use a black-like nunchuk

Signed-off-by: Miquel Raynal <[email protected]>

labs/kernel-i2c-describing-hardware/kernel-i2c-describing-hardware.tex

@@ -223,7 +223,11 @@ \subsection{Prepare the I2C device DT description}
   There are white and black nunchuks, which don't expect the same
   initialization flow. We could imagine a boolean property named
   \code{nintendo,alternate-init} which will change the initialization
-  logic. See the nunchuk pdf for details about the alternate flow.
+  logic. See the nunchuk pdf for details about the alternate flow, but if you
+  are attending an on-site session, mind the nunchuk you got behaves like a
+  black, even though it looks very white\footnote{The Nunchuk copies we
+  carry got a white cover even though their electronics behaves like the
+  orginal black version.}.
 
 \end{itemize}