There are four INA3221 chips on the Jetson TX2 (p3310 + p2771).
And each INA3221 chip has three input channels to monitor power.

So this patch adds these 12 channels to the DT of Jetson TX2, by
following the DT binding of INA3221 and official documents from
https://developer.nvidia.com/embedded/downloads

tegra186-p3310:
https://developer.nvidia.com/embedded/dlc/jetson-tx2-series-modules-oem-product-design-guide

tegra186-p2771-0000:
http://developer.nvidia.com/embedded/dlc/jetson-tx1-tx2-developer-kit-carrier-board-spec-20180618Signed-off-by: Nicolin Chen <nicoleotsuka@gmail.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>