fmap: publish find_fmap_directory()

The fmap directory can be useful to pass to the payload. For that, we need to
be able to get it.

Change-Id: Ibe0be73bb4fe28afb16d4d215b979eb0be369645
Signed-off-by: Patrick Georgi <pgeorgi@chromium.org>
Reviewed-on: http://review.coreboot.org/10866
Tested-by: build bot (Jenkins)
Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>
Reviewed-by: Aaron Durbin <adurbin@chromium.org>

src/lib/fmap.c

@@ -28,7 +28,7 @@
  * See http://code.google.com/p/flashmap/ for more information on FMAP.
  */
 
-static int find_fmap_directory(struct region_device *fmrd)
+int find_fmap_directory(struct region_device *fmrd)
 {
 	const struct region_device *boot;
 	struct fmap *fmap;