Device-Tree bindings for MediaTek MT5896 SoC based RTC

Required properties:
- compatible	    : Should be
			"mediatek,mt5896-spi" : for MT5896 SoC
- reg 		    : Specifies base physical address and size of the registers;

Example:

	mspi@1c640800 {
		compatible = "mediatek,mt5896-spi";
		interrupt-parent = <&mtk_intc2_irq_low>;
		interrupts = <0x0 0x5 0x4>;
		reg = <0 0x1c640800 0 0x200>;
		spidev@1{
			compatible = "spidev";
			reg = <0>;
			spi-max-frequency = <2000000>;
			};
	};
