cbfstool: Deserialize CBFS master header when reading image

Rather than  using [hn]to[nh] whenever accessing a member of the CBFS
header, deserialize the header when opening the CBFS image. The header
is no longer a pointer inside the CBFS buffer, but a separate struct,
a copy of the original header in a host-friendly format. This kills
more of the ntohl usage.

Change-Id: I5f8a5818b9d5a2d1152b1906249c4a5847d02bac
Signed-off-by: Alexandru Gagniuc <mr.nuke.me@gmail.com>
Reviewed-on: http://review.coreboot.org/5121
Tested-by: build bot (Jenkins)
Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>
Reviewed-by: Ronald G. Minnich <rminnich@gmail.com>
diff --git a/util/cbfstool/cbfstool.c b/util/cbfstool/cbfstool.c
index 1d93981..792dd91 100644
--- a/util/cbfstool/cbfstool.c
+++ b/util/cbfstool/cbfstool.c
@@ -436,7 +436,7 @@
 	}
 
 	if (param.top_aligned)
-		address = address - ntohl(image.header->romsize);
+		address = address - image.header->romsize;
 
 	cbfs_image_delete(&image);
 	printf("0x%x\n", address);