cmd: bootz: fix device-tree overlap test

The address of the kernel image is stored in images->ep. zi_start is the
offset of execution entry in the image, which is usually 0 for ARM
zImage.

Fixes boot error when ftd is stored near RAM address 0x0:

ERROR: FDT image overlaps OS image (OS=0x0..0x5fd608)

Fixes: fbde7589ce30 ("common: bootm: add checks to verify if ramdisk / fdtimage overlaps OS image")
Cc: Tero Kristo <t-kristo@ti.com>
Signed-off-by: Baruch Siach <baruch@tkos.co.il>
diff --git a/cmd/bootz.c b/cmd/bootz.c
index 1c8b0cf..7556cd2 100644
--- a/cmd/bootz.c
+++ b/cmd/bootz.c
@@ -54,7 +54,7 @@
 	 * Handle the BOOTM_STATE_FINDOTHER state ourselves as we do not
 	 * have a header that provide this informaiton.
 	 */
-	if (bootm_find_images(flag, argc, argv, zi_start, zi_end - zi_start))
+	if (bootm_find_images(flag, argc, argv, images->ep, zi_end - zi_start))
 		return 1;
 
 	return 0;