dt-bindings: hwmon: lm70: move to trivial devices

The lm70 thermometer bindings are trivial, so like many other I2C/SPI
temperature sensors can be integrated into trivial devices bindings.

Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20210920182114.339419-1-krzysztof.kozlowski@canonical.com


Signed-off-by: Guenter Roeck <linux@roeck-us.net>