mfd: simple-mfd-i2c: Add MAX77705 support

Add MAX77705 support - fuel gauge and hwmon devices.
Hwmon provides charger input and system bus measurements.

Signed-off-by: Dzmitry Sankouski <dsankouski@gmail.com>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://lore.kernel.org/r/20250123-starqltechn_integration_upstream-v17-4-8b06685b6612@gmail.com


Signed-off-by: Lee Jones <lee@kernel.org>