fmaptool: Introduce the fmd ("flashmap descriptor") language and compiler

This adds a compiler for a language whose textual representation of flashmap
regions will be used to describe the layout of flash chips that contain more
than just a single CBFS. Direct integration with cbfstool (via a new
command-line switch for the create action) is forthcoming but will be added
separately.

BUG=chromium:461875
TEST=Use Chromium OS's cros_bundle_firmware script on the fmap.dts file for
panther. Using the latter file as a reference, write a corresponding
fmap.fmd file and feed it through fmaptool. Run both binary output files
though the flashmap project's own flashmap_decode utility. Observe only
the expected differences.
BRANCH=None

Change-Id: I06b32d138dbef0a4e5ed43c81bd31c796fd5d669
Signed-off-by: Sol Boucher <solb@chromium.org>
Original-Commit-Id: 005ab67eb594e21489cf31036aedaea87e0c7142
Original-Change-Id: Ia08f28688efdbbfc70c255916b8eb7eb0eb07fb2
Original-Signed-off-by: Sol Boucher <solb@chromium.org>
Original-Reviewed-on: https://chromium-review.googlesource.com/255031
Original-Reviewed-by: Julius Werner <jwerner@chromium.org>
Original-Reviewed-by: Stefan Reinauer <reinauer@chromium.org>
Reviewed-on: http://review.coreboot.org/9942
Tested-by: build bot (Jenkins)
Reviewed-by: Patrick Georgi <pgeorgi@google.com>
diff --git a/util/cbfstool/flashmap/kv_pair.h b/util/cbfstool/flashmap/kv_pair.h
index 9257a26..7024dd3 100644
--- a/util/cbfstool/flashmap/kv_pair.h
+++ b/util/cbfstool/flashmap/kv_pair.h
@@ -56,7 +56,7 @@
 	struct kv_pair *next;
 };
 
-extern enum kv_pair_style kv_pair_get_style();
+extern enum kv_pair_style kv_pair_get_style(void);
 
 extern void kv_pair_set_style(enum kv_pair_style style);