Raise a warning if old syntax for sha256 is used
Raise a warning if old syntax for sha256 is used

Generation of attributes in sw-description should be done by separate
function. The old syntax with '@<artifact name>' is still allowed for
compatibility reason, but it will be removed in future.

Signed-off-by: Stefano Babic <2c2905e0c2877c7e4ce40c7425e972302953fda5@denx.de>

sbabic/meta-swupdate,sbabic/meta-swupdate