build system: Move manual cbfstool add* invocations to cbfs-files

Use cbfs-files-y to deal with some of the manually added cbfs files,
providing more structure to that part of the build.

Change-Id: Iee1b8fec81dfa5e5f0e55637a62e5f69bd0257ad
Signed-off-by: Patrick Georgi <pgeorgi@chromium.org>
Reviewed-on: https://review.coreboot.org/12538
Tested-by: build bot (Jenkins)
Reviewed-by: Martin Roth <martinroth@google.com>
1 file changed