dt-bindings: gpio: spacemit: add support for K1 SoC

dt-bindings: gpio: spacemit: add support for K1 SoC

The GPIO controller of K1 support basic functions as input/output,
all pins can be used as interrupt which route to one IRQ line,
trigger type can be select between rising edge, falling edge, or both.
There are four GPIO banks, each consisting of 32 pins.

Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Rob Herring (Arm) <robh@kernel.org>
Signed-off-by: Yixun Lan <dlan@gentoo.org>
Link: https://lore.kernel.org/r/20250412-03-k1-gpio-v8-1-1c6862d272ec@gentoo.org
Signed-off-by: Bartosz Golaszewski <brgl@bgdev.pl>