dt-binding: i3c: Document Synopsys DesignWare I3C

Document Synopsys DesignWare I3C master module
Signed-off-by: Vitor Soares <vitor.soares@synopsys.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com>

Documentation/devicetree/bindings/i3c/snps,dw-i3c-master.txt

+Bindings for Synopsys DesignWare I3C master block
+=================================================
+
+Required properties:
+--------------------
+- compatible: shall be "snps,dw-i3c-master-1.00a"
+- clocks: shall reference the core_clk
+- interrupts: the interrupt line connected to this I3C master
+- reg: Offset and length of I3C master registers
+
+Mandatory properties defined by the generic binding (see
+Documentation/devicetree/bindings/i3c/i3c.txt for more details):
+
+- #address-cells: shall be set to 3
+- #size-cells: shall be set to 0
+
+Optional properties defined by the generic binding (see
+Documentation/devicetree/bindings/i3c/i3c.txt for more details):
+
+- i2c-scl-hz
+- i3c-scl-hz
+
+I3C device connected on the bus follow the generic description (see
+Documentation/devicetree/bindings/i3c/i3c.txt for more details).
+
+Example:
+
+	i3c-master@2000 {
+		compatible = "snps,dw-i3c-master-1.00a";
+		#address-cells = <3>;
+		#size-cells = <0>;
+		reg = <0x02000 0x1000>;
+		interrupts = <0>;
+		clocks = <&i3cclk>;
+
+		eeprom@57{
+			compatible = "atmel,24c01";
+			reg = <0x57 0x0 0x10>;
+			pagesize = <0x8>;
+		};
+	};