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/nios2/dts/10m50_devboard.dts b/arch/nios2/dts/10m50_devboard.dts
index 9cd4016..df64596 100644
--- a/arch/nios2/dts/10m50_devboard.dts
+++ b/arch/nios2/dts/10m50_devboard.dts
@@ -18,7 +18,7 @@
 		#size-cells = <0>;
 
 		cpu: cpu@0 {
-			u-boot,dm-pre-reloc;
+			bootph-all;
 			device_type = "cpu";
 			compatible = "altr,nios2-1.1";
 			reg = <0x00000000>;