Add support so that rimage can take as it's input multiple ELF modules
and merge them into a single signed manifest and firmware binary.
Remove all hard coded module descriptions. Module metadata is now read
from the ELF "module" section.
Remove duplicated and unused code for creating simple firmware images as
used on Baytrail and Haswell.
Signed-off-by: Liam Girdwood <liam.r.girdwood@linux.intel.com>