This is only useful for Sandbox. Use the -d flag to U-Boot to
specify the file to read.
+config OF_PRIOR_STAGE
+ bool "Prior stage bootloader DTB for DT control"
+ help
+ If this option is enabled, the device tree used for DT
+ control will be read from a device tree binary, at a memory
+ location passed to U-Boot by the prior stage bootloader.
+
endchoice
config DEFAULT_DEVICE_TREE