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/imx8mn-bsh-smm-s2-u-boot-common.dtsi b/arch/arm/dts/imx8mn-bsh-smm-s2-u-boot-common.dtsi
index 3967e0b..19b0d89 100644
--- a/arch/arm/dts/imx8mn-bsh-smm-s2-u-boot-common.dtsi
+++ b/arch/arm/dts/imx8mn-bsh-smm-s2-u-boot-common.dtsi
@@ -7,49 +7,49 @@
 #include "imx8mn-u-boot.dtsi"
 
 &{/soc@0/bus@30800000/i2c@30a20000/pmic@4b} {
-	u-boot,dm-spl;
+	bootph-pre-ram;
 };
 
 &{/soc@0/bus@30800000/i2c@30a20000/pmic@4b/regulators} {
-	u-boot,dm-spl;
+	bootph-pre-ram;
 };
 
 &gpio1 {
-	u-boot,dm-spl;
+	bootph-pre-ram;
 };
 
 &gpio2 {
-	u-boot,dm-spl;
+	bootph-pre-ram;
 };
 
 &gpio4 {
-	u-boot,dm-spl;
+	bootph-pre-ram;
 };
 
 &i2c1 {
-	u-boot,dm-spl;
+	bootph-pre-ram;
 };
 
 &pinctrl_i2c1 {
-	u-boot,dm-spl;
+	bootph-pre-ram;
 };
 
 &pinctrl_pmic {
-	u-boot,dm-spl;
+	bootph-pre-ram;
 };
 
 &pinctrl_uart4 {
-	u-boot,dm-spl;
+	bootph-pre-ram;
 };
 
 &pinctrl_wdog {
-	u-boot,dm-spl;
+	bootph-pre-ram;
 };
 
 &uart4 {
-	u-boot,dm-spl;
+	bootph-pre-ram;
 };
 
 &wdog1 {
-	u-boot,dm-spl;
+	bootph-pre-ram;
 };