This commit fixes the cross-arch uploading in the most simple
case by reading the `--arch` when `image-builder build --upload`
is used. Note that this is not a complete fix as it will not
take boot mode into account nor will it (by default) DTRT when
`image-builder upload` is used on a previously build images
for a different architecture.
Thanks to `FrostyX` for reporting the issue.
This commit adds support to upload the build image directly to
the target cloud. Currently only ami/AWS is supported.
If the cloud specific configuration is given at the commandline
and the image type is a cloud image the cloud upload will happen
automatically (just like with bib). Incomplete upload config is
an error.