dt-bindings: hwmon: lltc,ltc4286: use common hwmon schema

Reference common hwmon schema which allows to drop the
"shunt-resistor-micro-ohms" property.

Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://lore.kernel.org/r/20240224-dt-bindings-hwmon-common-v2-4-b446eecf5480@linaro.org


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