It turns out that the i2c1 adapter is connected to a multiplexer
controlled by a gpio line. The first (default) mux option connects
i2c1 to a bus connected to the already known peripherals. The other
one connects the adapter to the ddc pins of the DVI port.
Signed-off-by: NChristopher Spinrath <christopher.spinrath@rwth-aachen.de>
Signed-off-by: NShawn Guo <shawnguo@kernel.org>