Revision 4054

I thought that romfs infrastructure is done now, but there were some
issues (see buildbot).
The romfs image was always built, and sometimes broke (because of
the different image layouts) for buildrom images. After the patch, these
issues are avoided by not adding payloads to the romfs image (they
wouldn't be read anyway). Both workarounds (in buildrom code for
romfs and vice-versa) aren't very pretty, but that's what our buildsystem
requires.
As I had to create a "communication channel" (via the romfs-support
files), I took the chance to also use it for compression
information, so if you configure lzma support, you'll get lzma
compressed payloads in romfs.

Signed-off-by: Patrick Georgi <patrick.georgi@coresystems.de>
Acked-by: Stefan Reinauer <stepan@coresystems.de>