app: aboot: Update the kernel/ramdisk/tags addr to use sane values

Use sane values for kernel/ramdisk/tags address if the boot image
header contains default values. These default values come from
mkbootimg when the kernel & ramdisk are flashed using fastboot
flash:raw

Change-Id: I9b2d5b9c04337f3b942fd6483ec03cad200ce7fc
1 file changed