You want to have your spi setup like this:

			spi0: spi@f8000000 {
				pinctrl-names = "default";
				pinctrl-0 = <&pinctrl_spi0_default>;
				cs-gpios = <&pioA PIN_PB1 0>, <0>, <0>, <0>;
				status = "okay";

				spidev@0 {
					compatible = "linux,spidev";
					spi-max-frequency = <24000000>;
					reg = <0>;
				};
			};

and then I use this command:
modprobe fbtft_device txbuflen=32768 busnum=0 custom name=fb_ili9341 speed=24000000 gpios=reset:37,dc:39 bgr=1 rotate=90 fps=30