ARM: at91: sama5d4: dts: change the nand compatible string

As we introduce a new "atmel,sama5d4-nand" compatible string for sama5d4,
so we need to apply it for sama5d4 chip.
Signed-off-by: Josh Wu <josh.wu@atmel.com>
Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>

arch/arm/boot/dts/sama5d4.dtsi

@@ -273,7 +273,7 @@ L2: cache-controller@00a00000 {
 		};
 
 		nand0: nand@80000000 {
-			compatible = "atmel,at91rm9200-nand";
+			compatible = "atmel,sama5d4-nand", "atmel,at91rm9200-nand";
 			#address-cells = <1>;
 			#size-cells = <1>;
 			ranges;