dt-bindings: gpio: Add max77759 binding

dt-bindings: gpio: Add max77759 binding

The Maxim MAX77759 is a companion PMIC for USB Type-C applications and
includes Battery Charger, Fuel Gauge, temperature sensors, USB Type-C
Port Controller (TCPC), NVMEM, and a GPIO expander.

This describes its GPIO module.

Signed-off-by: André Draszik <andre.draszik@linaro.org>
Reviewed-by: "Rob Herring (Arm)" <robh@kernel.org>
Acked-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Link: https://lore.kernel.org/r/20250325-max77759-mfd-v6-1-c0870ca662ba@linaro.org
Signed-off-by: Lee Jones <lee@kernel.org>