dm: dts: Convert driver model tags to use new schema

Now that Linux has accepted these tags, move the device tree files in
U-Boot over to use them.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/arch/arm/dts/imx6ul-opos6ul-u-boot.dtsi b/arch/arm/dts/imx6ul-opos6ul-u-boot.dtsi
index 4918de3..ebfb95d 100644
--- a/arch/arm/dts/imx6ul-opos6ul-u-boot.dtsi
+++ b/arch/arm/dts/imx6ul-opos6ul-u-boot.dtsi
@@ -7,22 +7,22 @@
 
 / {
 	soc {
-		u-boot,dm-spl;
+		bootph-pre-ram;
 	};
 };
 
 &aips2 {
-	u-boot,dm-spl;
+	bootph-pre-ram;
 };
 
 &iomuxc {
-	u-boot,dm-spl;
+	bootph-pre-ram;
 };
 
 &pinctrl_usdhc1 {
-	u-boot,dm-spl;
+	bootph-pre-ram;
 };
 
 &usdhc1 {
-	u-boot,dm-spl;
+	bootph-pre-ram;
 };