* Realtek rts39xx SoC Ethernet controller

Required properties/subnode:
- compatible: Should be "realtek,rts3903-r8168"
- reg: Address and length of the register set for the device
- interrupt-parent: Phandle of the parent interrupt controller
- interrupts: Should contain ethernet controller interrupt
- pinctrl-names, pinctrl-0
	Please refer to pinctrl-bindings.txt.
- resets: List of phandle and reset specifier pairs, one pair for each reset signal that affects the device.
- reset-names: List of reset signal name strings sorted in the same order as the resets property.
- led_configs node: Ethernet status led configuration. Additional information is below.
led_configs subnode indicates how the ethernet status leds work.

Required properties:
- led-pin: 1 means the led works, -1 means the led doesn't work.
- link-mode: led blinks whether ethernet works on 10M, 100M or 1000M mode.
- act-full: 1 means led works on all speed link, 0 means led works only on selected speed link.
- act-high-active: 1 means led high active, 0 means led low active.

Optional properties:
- extern_phy: enable this to support the external ldphy.
- extern_phy_reset_gpio: externel phy reset pin number.

Example:
		eth0: rtl8168@18400000 {
			compatible = "realtek,rts3915-r8168";
			reg = <0x18400000 0x10000 0x18861000 0x1000>;
			interrupt-parent = <&cpuintc>;
			interrupts = <BSP_IRQ_ETHERNET>;
			pinctrl-names = "default";
			pinctrl-0 = <&eth_default_mode>;
			resets = <&reset FORCE_RESET_ETHERNET>,            \
					<&reset FORCE_RESET_FEPHY>, \
					<&sysmem SYS_MEM_SD_ETH>;
			reset-names = "eth-reset", "fephy-reset", "eth-mem-up";
			status = "disabled";
			extern_phy;
			extern_phy_reset_gpio = <&pinctrl 15 GPIO_ACTIVE_HIGH>;

			led_configs {
				led_config@0 {
					led-pin = <1>;
					link-mode = <100>;
					act-full = <1>;
					act-high-active = <0>;
				};
				led_config@1 {
					led-pin = <1>;
					link-mode = <100>;
					act-full = <1>;
					act-high-active = <0>;
				};
				led_config@2 {
					led-pin = <1>;
					link-mode = <100>;
					act-full = <1>;
					act-high-active = <0>;
				};
			};
		};
