* Realtek rts39xx spi nand flash controller

Required properties/subnode:
- compatible: Should be "realtek,rts3903-quadspi-nfc"
- reg: Address and length of the register set for the device
- interrupt-parent: Phandle of the parent interrupt controller
- interrupts: Should contain sdio controller interrupt
- clocks : Clock specifiers
- clock-names : identifier string for clock specifiers
- resets : list of two reset specifiers
- reset-names:  identifier string for reset specifiers

Example:
	spi0: spic@0x18030000 {
		compatible = "realtek,rts3903-quadspi-nfc";
		#address-cells = <1>;
		#size-cells = <0>;
		reg = <0x18030000 0x10000>;
		clocks = <&clks RLX_CLK_BUS_CK>;
		clock-names = "spi_ck";
		spi-max-frequency = <60000000>;
		interrupt-parent = <&cpuintc>;
		interrupts = <BSP_IRQ_SPI>;
		resets = <&sysmem SYS_MEM_SD_NAND_SPIC>;
		reset-names = "spi-nand-sysmem-up";
	};
