board: ti: am64x: am64x.env: set fdtfile env variable

Set fdtfile env variable similar to other k3 socs.

Signed-off-by: Kamlesh Gurudasani <kamlesh@ti.com>
Signed-off-by: Manorit Chawdhry <m-chawdhry@ti.com>
Reviewed-by: Nikhil M Jain <n-jain1@ti.com>
diff --git a/board/ti/am64x/am64x.env b/board/ti/am64x/am64x.env
index c3960be..2a1a1fa 100644
--- a/board/ti/am64x/am64x.env
+++ b/board/ti/am64x/am64x.env
@@ -9,6 +9,7 @@
 		setenv name_fdt k3-am642-sk.dtb; fi;
 	if test $name_fdt = undefined; then
 		echo WARNING: Could not determine device tree to use; fi;
+	setenv fdtfile ${name_fdt}
 name_kern=Image
 console=ttyS2,115200n8
 args_all=setenv optargs earlycon=ns16550a,mmio32,0x02800000 ${mtdparts}