cbfstool: add ppc64 support

The constant for ppc64 is 'hotstuff'. For many reasons.

Note that line 2894 of elf.h is not indented. This is because in the
original the line begins with a space. Checkpatch rejects that.
Checkpatch also rejects changing the space to a tab because that makes
it more than 80 chars. I rejected breaking the line because it makes it
even less readable. All the changes forced by checkpatch make the code
less readable.

Herman Hollerith would be proud.

Change-Id: I21f049fe8c655a30f17dff694b8f42789ad9efb7
Signed-off-by: Ronald G. Minnich <rminnich@gmail.com>
Reviewed-on: https://review.coreboot.org/12711
Reviewed-by: Timothy Pearson <tpearson@raptorengineeringinc.com>
Tested-by: build bot (Jenkins)

util/cbfstool/cbfs.h

@@ -72,6 +72,7 @@ struct cbfs_header {
 #define CBFS_ARCHITECTURE_AARCH64  0x0000aa64
 #define CBFS_ARCHITECTURE_MIPS     0x00000100
 #define CBFS_ARCHITECTURE_RISCV    0xc001d0de
+#define CBFS_ARCHITECTURE_PPC64    0x407570ff
 
 #define CBFS_FILE_MAGIC "LARCHIVE"