kernel-fitImage: Remove dependeny on initramfs image when bundled.

kernel-fitImage: Remove dependeny on initramfs image when bundled.

In case the initramfs image is bundled into the kernel there's no need to
specify a dependeny on the do_image_complete task of the initramfs image
from the do_assemble_fitimage_initramfs task since the task won't access
the image.

Signed-off-by: Weisser, Pascal <pascal.weisser.ext@karlstorz.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>