arm: dts: enable MTK SPI NOR controller driver

1. Enable MTK SPI NOR controller driver on mt7622 & mt7629.
2. Enable quad mode for read and single mode for write.

diff --git a/arch/arm/dts/mt7622.dtsi b/arch/arm/dts/mt7622.dtsi
index 5c2e025..0127474 100644
--- a/arch/arm/dts/mt7622.dtsi
+++ b/arch/arm/dts/mt7622.dtsi
@@ -53,6 +53,17 @@
 		#size-cells = <0>;
 	};
 
+	snor: snor@11014000 {
+		compatible = "mediatek,mtk-snor";
+		reg = <0x11014000 0x1000>;
+		clocks = <&pericfg CLK_PERI_FLASH_PD>,
+			 <&topckgen CLK_TOP_FLASH_SEL>;
+		clock-names = "spi", "sf";
+		status = "disabled";
+		#address-cells = <1>;
+		#size-cells = <0>;
+	};
+
 	timer {
 		compatible = "arm,armv8-timer";
 		interrupt-parent = <&gic>;