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/imx8mm-venice-gw7902-u-boot.dtsi b/arch/arm/dts/imx8mm-venice-gw7902-u-boot.dtsi
index d58a7d1..91b33a9 100644
--- a/arch/arm/dts/imx8mm-venice-gw7902-u-boot.dtsi
+++ b/arch/arm/dts/imx8mm-venice-gw7902-u-boot.dtsi
@@ -176,17 +176,17 @@
 };
 
 &pinctrl_fec1 {
-	u-boot,dm-spl;
+	bootph-pre-ram;
 };
 
 &{/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;
 };
 
 &pinctrl_pmic {
-	u-boot,dm-spl;
+	bootph-pre-ram;
 };