arm64: dts: ls1046a-qds: Modify the qspi flash frequency

The qspi flash in ls1046a QDS board can operate at 50MHz frequency.
Therefore, update the maximum supported freq in dts file.
Signed-off-by: Pankaj Bansal <pankaj.bansal@nxp.com>
Signed-off-by: Li Yang <leoyang.li@nxp.com>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>

arch/arm64/boot/dts/freescale/fsl-ls1046a-qds.dts

@@ -182,7 +182,7 @@ qflash0: flash@0 {
 		compatible = "spansion,m25p80";
 		#address-cells = <1>;
 		#size-cells = <1>;
-		spi-max-frequency = <20000000>;
+		spi-max-frequency = <50000000>;
 		spi-rx-bus-width = <4>;
 		spi-tx-bus-width = <4>;
 		reg = <0>;