mips: bmips: add bcm63xx-spi driver support for BCM63268

This driver manages the low speed SPI controller present on this SoC.

Signed-off-by: Álvaro Fernández Rojas <noltari@gmail.com>
Reviewed-by: Daniel Schwierzeck <daniel.schwierzeck@gmail.com>
Reviewed-by: Jagan Teki <jagan@openedev.com>
Reviewed-by: Simon Glass <sjg@chromium.org>

arch/mips/dts/brcm,bcm63268.dtsi

@@ -13,6 +13,10 @@
 / {
 	compatible = "brcm,bcm63268";
 
+	aliases {
+		spi0 = &lsspi;
+	};
+
 	cpus {
 		reg = <0x10000000 0x4>;
 		#address-cells = <1>;
@@ -136,6 +140,19 @@
 			#power-domain-cells = <1>;
 		};
 
+		lsspi: spi@10000800 {
+			compatible = "brcm,bcm6358-spi";
+			reg = <0x10000800 0x70c>;
+			#address-cells = <1>;
+			#size-cells = <0>;
+			clocks = <&periph_clk BCM63268_CLK_SPI>;
+			resets = <&periph_rst BCM63268_RST_SPI>;
+			spi-max-frequency = <20000000>;
+			num-cs = <8>;
+
+			status = "disabled";
+		};
+
 		leds: led-controller@10001900 {
 			compatible = "brcm,bcm6328-leds";
 			reg = <0x10001900 0x24>;