Add multi-architecture support to cbfstool

This is an initial re-factoring of CBFS code to enable multiple
architectures. To achieve a clean solution, an additional field
describing the architecture has to be added to the master header.
Hence we also increase the version number in the master header.

Change-Id: Icda681673221f8c27efbc46f16c2c5682b16a265
Signed-off-by: Stefan Reinauer <reinauer@google.com>
Signed-off-by: Hung-Te Lin <hungte@chromium.org>
Signed-off-by: David Hendricks <dhendrix@chromium.org>
Reviewed-on: http://review.coreboot.org/1944
Tested-by: build bot (Jenkins)

payloads/coreinfo/cbfs_module.c

@@ -41,7 +41,8 @@ struct cbheader {
 	u32 bootblocksize;
 	u32 align;
 	u32 offset;
-	u32 pad[2];
+	u32 architecture;
+	u32 pad[1];
 } __attribute__ ((packed));
 
 struct cbfile {