arm64: dts: exynos: gs101-pixel-common: add nvmem-reboot-mode

Add the 'nvmem-reboot-mode' which is used to communicate a requested
boot mode to the boot loader.

Signed-off-by: André Draszik <andre.draszik@linaro.org>
Reviewed-by: Peter Griffin <peter.griffin@linaro.org>
Link: https://lore.kernel.org/r/20250524-b4-max77759-mfd-dts-v2-3-b479542eb97d@linaro.org


Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>