Revert "x86: bootm: Fix FIT image booting on x86"

Revert "x86: bootm: Fix FIT image booting on x86"

This reverts commit d8d03f24025f21065db6ef2f4d5f0c74da68eb76.

The error message with FIT style image mentioned in the above commit
only happens when booting using FIT image containing bzImage kernel
and without setup node (setup.bin). The current documentation for
x86 FIT support in doc/uImage.FIT/x86-fit-boot.txt mentions that
kernel's setup.bin file is required for building x86 FIT images.
The above commit breaks FIT images generated as described in the
documentation. Revert it to allow booting with images built in the
documented way.

Signed-off-by: Anatolij Gustschin <agust@denx.de>
Reviewed-by: Stefan Roese <sr@denx.de>
Acked-by: Bin Meng <bmeng.cn@gmail.com>