dt-bindings: timer: Add ABIs for new Ingenic SoCs

1.Add OST_CLK_EVENT_TIMER for new XBurst®1 SoCs.
2.Add OST_CLK_EVENT_TIMER0 to OST_CLK_EVENT_TIMER15 for new XBurst®2 SoCs.

Signed-off-by: 周琰杰 (Zhou Yanjie) <zhouyanjie@wanyeetech.com>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/1626370605-120775-1-git-send-email-zhouyanjie@wanyeetech.com