media: dt-bindings: allwinner: document H6 Hantro G2 binding

Allwinner H6 contains older Hantro G2 core, primarly used for VP9 video
decoding. It's unclear for now if HEVC is also supported.

Describe its binding.
Signed-off-by: Jernej Skrabec <jernej.skrabec@gmail.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>

Documentation/devicetree/bindings/media/allwinner,sun50i-h6-vpu-g2.yaml

+# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
+
+%YAML 1.2
+---
+$id: "http://devicetree.org/schemas/media/allwinner,sun50i-h6-vpu-g2.yaml#"
+$schema: "http://devicetree.org/meta-schemas/core.yaml#"
+
+title: Hantro G2 VPU codec implemented on Allwinner H6 SoC
+
+maintainers:
+  - Jernej Skrabec <jernej.skrabec@gmail.com>
+
+description:
+  Hantro G2 video decode accelerator present on Allwinner H6 SoC.
+
+properties:
+  compatible:
+    const: allwinner,sun50i-h6-vpu-g2
+
+  reg:
+    maxItems: 1
+
+  interrupts:
+    maxItems: 1
+
+  clocks:
+    items:
+      - description: Bus Clock
+      - description: Module Clock
+
+  clock-names:
+    items:
+      - const: bus
+      - const: mod
+
+  resets:
+    maxItems: 1
+
+required:
+  - compatible
+  - reg
+  - interrupts
+  - clocks
+  - clock-names
+  - resets
+
+additionalProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/interrupt-controller/arm-gic.h>
+    #include <dt-bindings/clock/sun50i-h6-ccu.h>
+    #include <dt-bindings/reset/sun50i-h6-ccu.h>
+
+    video-codec-g2@1c00000 {
+        compatible = "allwinner,sun50i-h6-vpu-g2";
+        reg = <0x01c00000 0x1000>;
+        interrupts = <GIC_SPI 90 IRQ_TYPE_LEVEL_HIGH>;
+        clocks = <&ccu CLK_BUS_VP9>, <&ccu CLK_VP9>;
+        clock-names = "bus", "mod";
+        resets = <&ccu RST_BUS_VP9>;
+    };
+
+...