powerpc/fsl: Fix SPI compatible on t208xrdb and t1040rdb

On the t208xrdb and t1040rdb, the SPI device is n25q512ax3
instead of n25q512a.
Signed-off-by: Hou Zhiqiang <Zhiqiang.Hou@freescale.com>
Signed-off-by: Scott Wood <oss@buserror.net>

arch/powerpc/boot/dts/fsl/t104xrdb.dtsi

@@ -109,7 +109,7 @@ spi@110000 {
 			flash@0 {
 				#address-cells = <1>;
 				#size-cells = <1>;
-				compatible = "micron,n25q512a", "jedec,spi-nor";
+				compatible = "micron,n25q512ax3", "jedec,spi-nor";
 				reg = <0>;
 				spi-max-frequency = <10000000>; /* input clock */
 			};

arch/powerpc/boot/dts/fsl/t208xrdb.dtsi

@@ -113,7 +113,7 @@ spi@110000 {
 			flash@0 {
 				#address-cells = <1>;
 				#size-cells = <1>;
-				compatible = "micron,n25q512a", "jedec,spi-nor";
+				compatible = "micron,n25q512ax3", "jedec,spi-nor";
 				reg = <0>;
 				spi-max-frequency = <10000000>; /* input clock */
 			};