dt-bindings: thermal: Add binding for Tegra30 thermal sensor

All NVIDIA Tegra30 SoCs have on-chip sensors which monitor temperature
and voltage of the SoC. Sensors also controls CPU x2 freq throttle and
emits emergency shutdown signal. TSENSOR has has two separate channels
for each sensor placed in a different parts of the SoC. Add binding for
the sensor hardware.

Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/20210616190417.32214-2-digetx@gmail.com