am5728 sdk6.0对pru单emac支持问题

根据之前的询问了解sdk6.0的版本的pru驱动已经可以支持单emac驱动

我在移植完成新的sdk之后，按照doc/devicetree/binding/net/ti-prueth.txt更改了设备树，但是pru驱动会报访问空指针的错误

使用的设备树是am572x-idk.dtb,pru部分修改如下

pruss2_eth: pruss2_eth {
		compatible = "ti,am57-prueth";
		prus = <&pru2_0>, <&pru2_1>;
		//firmware-name = "ti-pruss/am57xx-pru0-prueth-fw.elf",
		firmware-name = "",
				"ti-pruss/am57xx-pru1-prueth-fw.elf";
		sram = <&ocmcram1>;
		interrupt-parent = <&pruss2_intc>;
		mii-rt = <&pruss2_mii_rt>;
		interrupts = <20>, <21>;
		interrupt-names = "rx_red_hp", "rx_red_lp";

		/*pruss2_emac0: ethernet-mii0 {
			phy-handle = <&pruss2_eth0_phy>;
			phy-mode = "mii";
			interrupts = <20>, <22>, <23>, <26>;
			interrupt-names = "rx", "tx", "hsrprp_ptp_tx",
					  "emac_ptp_tx";
			//Filled in by bootloader 
			local-mac-address = [00 00 00 00 00 00];
		};*/

		pruss2_emac1: ethernet-mii1 {
			phy-handle = <&pruss2_eth1_phy>;
			phy-mode = "mii";
			interrupts = <21>, <23>, <24>, <27>;
			interrupt-names = "rx", "tx", "hsrprp_ptp_tx",
					  "emac_ptp_tx";
			/* Filled in by bootloader */
			local-mac-address = [00 00 00 00 00 00];
		};
	};