arm64: dts: imx8dxl-evk: Remove invalid spi property

nxp,fspi-dll-slvdly is not documented nor used anywhere.

Drop this invalid property.
Signed-off-by: Fabio Estevam <festevam@denx.de>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>

arch/arm64/boot/dts/freescale/imx8dxl-evk.dts

@@ -186,7 +186,6 @@ vddio1: vddio-regulator {
 &flexspi0 {
 	pinctrl-names = "default";
 	pinctrl-0 = <&pinctrl_flexspi0>;
-	nxp,fspi-dll-slvdly = <4>;
 	status = "okay";
 
 	mt35xu512aba0: flash@0 {