cbfstool: Add the MIPS architecture

Specify a CBFS architecture value for MIPS and allow cbfstool to make
use of it.

Original-Change-Id: I604d61004596b65c9903d444e030241f712202bd
Original-Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Original-Reviewed-on: https://chromium-review.googlesource.com/207971
Original-Reviewed-by: Stefan Reinauer <reinauer@chromium.org>
Original-Reviewed-by: David Hendricks <dhendrix@chromium.org>
(cherry picked from commit 7c4df61715df3767673841789d02fe5d1bd1d4a0)
Signed-off-by: Marc Jones <marc.jones@se-eng.com>

Change-Id: Ib30524f5e7e8c7891cb69fc8ed8f6a7e44ac3325
Reviewed-on: http://review.coreboot.org/8519
Tested-by: build bot (Jenkins)
Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>
Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>
Reviewed-by: Patrick Georgi <pgeorgi@google.com>

util/cbfstool/cbfstool.c

@@ -590,7 +590,7 @@ static void usage(char *name)
 			"Updates the FIT table with microcode entries\n"
 	     "\n"
 	     "ARCHes:\n"
-	     "  arm64, arm, x86\n"
+	     "  arm64, arm, mips, x86\n"
 	     "TYPEs:\n", name, name
 	    );
 	print_supported_filetypes();