arm64: dts: rockchip: Add power button for puma-haikou

arm64: dts: rockchip: Add power button for puma-haikou

There is a PWRBTN# input pin exposed on a Q7 connector. The pin
is routed to a GPIO0_A1 through a diode. Q7 specification describes
the PWRBTN# pin as a Power Button signal.
Configure the pin as KEY_POWER, so it can function as power button and
trigger device shutdown.

Signed-off-by: Daniel Semkowicz <dse@thaumatec.com>
Reviewed-by: Quentin Schulz <quentin.schulz@cherry.de>
Link: https://lore.kernel.org/r/20241001134741.210979-1-dse@thaumatec.com
Signed-off-by: Heiko Stuebner <heiko@sntech.de>