dt-bindings: timer: rk-timer: Add rktimer for rv1126

Add rockchip timer compatible string for rockchip rv1126.

Signed-off-by: Jagan Teki <jagan@edgeble.ai>
Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://lore.kernel.org/r/20221123183124.6911-3-jagan@edgeble.ai


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