spi: sun6i: Add binding for Allwinner H3 SPI controller

H3 SPI has same architecture as A31 except FIFO capacity.
To configure the buffer size separately, compatible property should be
different. Optional DMA specifiers and example are added.
Signed-off-by: NMilo Kim <woogyom.kim@gmail.com>
Acked-by: NMaxime Ripard <maxime.ripard@free-electrons.com>
Acked-by: NRob Herring <robh+dt@kernel.org>
Signed-off-by: NMark Brown <broonie@kernel.org>

Documentation/devicetree/bindings/spi/spi-sun6i.txt

-Allwinner A31 SPI controller
+Allwinner A31/H3 SPI controller
 
 Required properties:
-- compatible: Should be "allwinner,sun6i-a31-spi".
+- compatible: Should be "allwinner,sun6i-a31-spi" or "allwinner,sun8i-h3-spi".
 - reg: Should contain register location and length.
 - interrupts: Should contain interrupt.
 - clocks: phandle to the clocks feeding the SPI controller. Two are
@@ -12,6 +12,11 @@ Required properties:
 - resets: phandle to the reset controller asserting this device in
           reset
 
+Optional properties:
+- dmas: DMA specifiers for rx and tx dma. See the DMA client binding,
+	Documentation/devicetree/bindings/dma/dma.txt
+- dma-names: DMA request names should include "rx" and "tx" if present.
+
 Example:
 
 spi1: spi@01c69000 {
@@ -22,3 +27,19 @@ spi1: spi@01c69000 {
 	clock-names = "ahb", "mod";
 	resets = <&ahb1_rst 21>;
 };
+
+spi0: spi@01c68000 {
+	compatible = "allwinner,sun8i-h3-spi";
+	reg = <0x01c68000 0x1000>;
+	interrupts = <GIC_SPI 65 IRQ_TYPE_LEVEL_HIGH>;
+	clocks = <&ccu CLK_BUS_SPI0>, <&ccu CLK_SPI0>;
+	clock-names = "ahb", "mod";
+	dmas = <&dma 23>, <&dma 23>;
+	dma-names = "rx", "tx";
+	pinctrl-names = "default";
+	pinctrl-0 = <&spi0_pins>;
+	resets = <&ccu RST_BUS_SPI0>;
+	status = "disabled";
+	#address-cells = <1>;
+	#size-cells = <0>;
+};