ARM: sun8i: v3s: enable SPI

Allwinner V3s SoC has a SPI controller, muxed with the MMC2 controller
at PC bank. The controller itself is identical to the one in H3 SoC.

Add device tree node and the only pinmux node for it.

Tested with a Winbond W25Q128FV SPI NOR soldered on the Lichee Pi
early sample.
Signed-off-by: Icenowy Zheng <icenowy@aosc.io>
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>

arch/arm/boot/dts/sun8i-v3s.dtsi

@@ -234,6 +234,11 @@ mmc1_pins: mmc1 {
 				drive-strength = <30>;
 				bias-pull-up;
 			};
+
+			spi0_pins: spi0 {
+				pins = "PC0", "PC1", "PC2", "PC3";
+				function = "spi0";
+			};
 		};
 
 		timer@01c20c00 {
@@ -314,6 +319,20 @@ i2c1: i2c@01c2b000 {
 			#size-cells = <0>;
 		};
 
+		spi0: spi@1c68000 {
+			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";
+			pinctrl-names = "default";
+			pinctrl-0 = <&spi0_pins>;
+			resets = <&ccu RST_BUS_SPI0>;
+			status = "disabled";
+			#address-cells = <1>;
+			#size-cells = <0>;
+		};
+
 		gic: interrupt-controller@01c81000 {
 			compatible = "arm,cortex-a7-gic", "arm,cortex-a15-gic";
 			reg = <0x01c81000 0x1000>,