this feature has never worked, the fw image name was not passed and the -t
parameter was missing in the tool invocation. drop the feature.
Signed-off-by: John Crispin <john@phrozen.org>
Use fwtool to extract it, only require metadata to be present if the
platform sysupgrade script sets REQUIRE_IMAGE_METADATA=1
Image metadata is in JSON format and contains a list of supported
devices, along with version information that could be displayed by a UI
later before the actual upgrade happens.
Signed-off-by: Felix Fietkau <nbd@nbd.name>