image: Don't detect XIP images as overlapping.

image: Don't detect XIP images as overlapping.

bootm_load_os() detects when it writes the decompressed image over
the top of the compressed image. If this happens, the original image
is corrupted. When the original image is a multi-component legacy image,
or a (potentially multi-component) FIT image, this implies that other
components may be corrupted. In turn, this means that booting is unlikely
to be successful.

However, in the case of no image compresssion coupled with an image with
load address equal to where the image is already located (e.g. an XIP
kernel, or IH_TYPE_KERNEL_ANYLOAD), there has been no copy and hence no
corruption, no matter whether it's a single-component legacy image, a
multi-component legacy image, or a FIT image. In this case, disable the
overlap detection, and allow boot to continue.

Without this change, when booting a single-component legacy image that
contains an IH_TYPE_KERNEL_ANYLOAD, bootm_load_os() would have returned
BOOTM_ERR_OVERLAP, but the caller ignores this, and boot continues and
succeeds. Now, the false error is no longer even returned.

Without this change, when booting a FIT image that contains an
IH_TYPE_KERNEL_ANYLOAD, bootm_load_os() would have returned
BOOTM_ERR_OVERLAP, which would then cause the caller to reset the board.
Now, the false error is no longer returned, and boot succeeds.

Signed-off-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Stefan Roese <sr@denx.de>