media: dt-bindings: Document the Rockchip VPU bindings

Add devicetree binding documentation for Rockchip Video Processing
Unit IP.
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Ezequiel Garcia <ezequiel@collabora.com>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>

Documentation/devicetree/bindings/media/rockchip-vpu.txt

+device-tree bindings for rockchip VPU codec
+
+Rockchip (Video Processing Unit) present in various Rockchip platforms,
+such as RK3288 and RK3399.
+
+Required properties:
+- compatible: value should be one of the following
+		"rockchip,rk3288-vpu";
+		"rockchip,rk3399-vpu";
+- interrupts: encoding and decoding interrupt specifiers
+- interrupt-names: should be "vepu" and "vdpu"
+- clocks: phandle to VPU aclk, hclk clocks
+- clock-names: should be "aclk" and "hclk"
+- power-domains: phandle to power domain node
+- iommus: phandle to a iommu node
+
+Example:
+SoC-specific DT entry:
+	vpu: video-codec@ff9a0000 {
+		compatible = "rockchip,rk3288-vpu";
+		reg = <0x0 0xff9a0000 0x0 0x800>;
+		interrupts = <GIC_SPI 9 IRQ_TYPE_LEVEL_HIGH>,
+			     <GIC_SPI 10 IRQ_TYPE_LEVEL_HIGH>;
+		interrupt-names = "vepu", "vdpu";
+		clocks = <&cru ACLK_VCODEC>, <&cru HCLK_VCODEC>;
+		clock-names = "aclk", "hclk";
+		power-domains = <&power RK3288_PD_VIDEO>;
+		iommus = <&vpu_mmu>;
+	};