dt-bindings: pinctrl: mediatek: mt7622: add "gpio-ranges" property

Allow specifying pin to GPIO mapping. It can be find in in-Linux DTS
file for MT7622.

Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
Acked-by: Krzysztof Kozlowski <krzk@kernel.org>
Message-ID: <20240408105128.30586-1-zajec5@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>