ARM: tegra: harmony: Add ADT7641 temperature sensor

The Harmony board has an Analog Devices ADT7461 temperature sensor
connected to the DVC bus. It can be used to monitor the ambient (local)
and on-die (remote) temperatures.

Signed-off-by: Thierry Reding <thierry.reding@avionic-design.de>
Tested-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Stephen Warren <swarren@nvidia.com>