dt-bindings: timer: rockchip: Add rk3576 compatible

Add compatible string for Rockchip RK3576 timer.

Signed-off-by: Detlev Casanova <detlev.casanova@collabora.com>
Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Acked-by: Heiko Stuebner <heiko@sntech.de>
Link: https://lore.kernel.org/r/20240802214612.434179-9-detlev.casanova@collabora.com


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