dt-bindings: gpio: Add devicetree binding for IDT 79RC32434 GPIO controller

Add YAML devicetree binding for IDT 79RC32434 GPIO controller

Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Reviewed-by: Rob Herring <robh@kernel.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>