Add a (b)zImage parser to cbfstool

In the great tradition of LinuxBIOS this allows adding
a kernel as payload. add-payload is extended to also
allow adding an initial ramdisk (-I filename) and a
command line (-C console=ttyS0).

Change-Id: Iaca499a98b0adf0134e78d6bf020b6531a626aaa
Signed-off-by: Patrick Georgi <patrick.georgi@secunet.com>
Signed-off-by: Patrick Georgi <patrick@georgi-clan.de>
Reviewed-on: http://review.coreboot.org/3302
Tested-by: build bot (Jenkins)
Reviewed-by: Ronald G. Minnich <rminnich@gmail.com>

util/cbfstool/cbfs-mkpayload.c

@@ -377,3 +377,4 @@ int parse_fv_to_payload(const struct buffer *input,
 	return 0;
 
 }
+