dt-bindings: timer: Add Ingenic X1000 OST bindings.

Add the OST bindings for the X1000 SoC from Ingenic.
Tested-by: 周正 (Zhou Zheng) <sernia.zhou@foxmail.com>
Signed-off-by: 周琰杰 (Zhou Yanjie) <zhouyanjie@wanyeetech.com>
Reviewed-by: Paul Cercueil <paul@crapouillou.net>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/20200722171804.97559-2-zhouyanjie@wanyeetech.com

Documentation/devicetree/bindings/timer/ingenic,sysost.yaml

+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/timer/ingenic,sysost.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Bindings for SYSOST in Ingenic XBurst family SoCs
+
+maintainers:
+  - 周琰杰 (Zhou Yanjie) <zhouyanjie@wanyeetech.com>
+
+description:
+  The SYSOST in an Ingenic SoC provides one 64bit timer for clocksource
+  and one or more 32bit timers for clockevent.
+
+properties:
+  "#clock-cells":
+    const: 1
+
+  compatible:
+    enum:
+      - ingenic,x1000-ost
+      - ingenic,x2000-ost
+
+  reg:
+    maxItems: 1
+
+  clocks:
+    maxItems: 1
+
+  clock-names:
+    const: ost
+
+  interrupts:
+    maxItems: 1
+
+required:
+  - "#clock-cells"
+  - compatible
+  - reg
+  - clocks
+  - clock-names
+  - interrupts
+
+additionalProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/clock/x1000-cgu.h>
+
+    ost: timer@12000000 {
+        compatible = "ingenic,x1000-ost";
+        reg = <0x12000000 0x3c>;
+
+        #clock-cells = <1>;
+
+        clocks = <&cgu X1000_CLK_OST>;
+        clock-names = "ost";
+
+        interrupt-parent = <&cpuintc>;
+        interrupts = <3>;
+    };
+...

include/dt-bindings/clock/ingenic,sysost.h

+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * This header provides clock numbers for the ingenic,tcu DT binding.
+ */
+
+#ifndef __DT_BINDINGS_CLOCK_INGENIC_OST_H__
+#define __DT_BINDINGS_CLOCK_INGENIC_OST_H__
+
+#define OST_CLK_PERCPU_TIMER	0
+#define OST_CLK_GLOBAL_TIMER	1
+
+#endif /* __DT_BINDINGS_CLOCK_INGENIC_OST_H__ */