dt-bindings: pinctrl: samsung: Add compatible for ARTPEC-8 SoC

Document the compatible string for ARTPEC-8 SoC pinctrl block,
which is similar to other Samsung SoC pinctrl blocks.

Signed-off-by: SeonGu Kang <ksk4725@coasia.com>
Signed-off-by: Ravi Patel <ravi.patel@samsung.com>
Acked-by: Rob Herring (Arm) <robh@kernel.org>
Link: https://lore.kernel.org/r/20250901051926.59970-2-ravi.patel@samsung.com


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