Hello Arun Kamath,
Uboot performs a detection of the board to select the appropriate device tree. However, you can set the device tree you want to use as part of the boot arguments:
setenv fdt_file <DEVICE TREE>
You can find more details on how to setup the boot arguments for different configurations on the i.MX Linux User’s Guide, which is available as part of the BSP documentation.
I hope this helps!
Regards,