the attached patch is the last infrastructure change necessary for

the attached patch is the last infrastructure change necessary for
romfs.
Everything else to make a target romfs aware happens in the targets.

What the patch does:
1. missing romfs.h include
2. special handling while creating coreboot.rom
While the romfs code path in the makefile doesn't actually use the file,
it's possible that the build of coreboot.rom fails in a romfs setup,
because the individual buildrom image is too small to host both coreboot
and payloads (as the payloads aren't supposed to be there). Thus, a
special case to replace the payload with /dev/null in case of a romfs
build.
There would be cleaner ways, but they're not easily encoded in the
Config.lb format.
3. config.g is changed to create rules for a romfs build

Targets should still build (they do for me)

Signed-off-by: Patrick Georgi <patrick.georgi@coresystems.de>
Acked-by: Stefan Reinauer <stepan@coresystems.de>
git-svn-id: svn://svn.coreboot.org/coreboot/trunk@4049 2b7e53f0-3cfb-0310-b3e9-8179ed1497e1