ok I got it working by modifying my dts file.
I am sharing it here for those who face the issue. So you dont have to waste days while pulling your hairs
/dts-v1/;
/plugin/;
/ {
compatible = "rockchip,rk3568"; /* Update to match your SoC */
fragment@0 {
target = <&spi3>; /* Correct SPI3 node */
__overlay__ {
#address-cells = <1>;
#size-cells = <0>;
pinctrl-names = "default";
pinctrl-0 = <&spi3m1_pins &spi3m1_cs0>; /* Reference correct pin configuration */
status = "okay"; /* Enable SPI3 */
spidev@0 {
compatible = "armbian,spi-dev";
reg = <0x00>;
spi-max-frequency = <5000000>;
status = "okay";
};
};
};
};
M. Hatef's post in Rock3A Armbian how to enable SPI3 was marked as the answer