dt-bindings: hwmon: ti,ina2xx: Add INA700

dt-bindings: hwmon: ti,ina2xx: Add INA700

Add a compatible string for INA700. The chip is register compatible with
INA780 but implements different ADC ranges and thus needs a separate
compatible entry.

Cc: Christian Kahr <christian.kahr@sie.at>
Reviewed-by: Chris Packham <chris.packham@alliedtelesis.co.nz>
Tested-by: Chris Packham <chris.packham@alliedtelesis.co.nz> # INA780
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>