clocksource/drivers/exynos_mct: Enable building on ARTPEC

This timer block is used on ARTPEC-8.

Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
Signed-off-by: Vincent Whitchurch <vincent.whitchurch@axis.com>
Link: https://lore.kernel.org/r/20220609112738.359385-5-vincent.whitchurch@axis.com


Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>