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/imx6sll-evk-u-boot.dtsi b/arch/arm/dts/imx6sll-evk-u-boot.dtsi
index 14d0b58..0e60906 100644
--- a/arch/arm/dts/imx6sll-evk-u-boot.dtsi
+++ b/arch/arm/dts/imx6sll-evk-u-boot.dtsi
@@ -4,5 +4,5 @@
  */
 
 &pinctrl_uart1 {
-	u-boot,dm-pre-reloc;
+	bootph-all;
 };