Eliminate version string duplication

Corresponding to flashrom svn r659.

Signed-off-by: Carl-Daniel Hailfinger <c-d.hailfinger.devel.2006@gmx.net>
Acked-by: Stefan Reinauer <stepan@coresystems.de>
diff --git a/flash.h b/flash.h
index ba201ec..0da4293 100644
--- a/flash.h
+++ b/flash.h
@@ -379,6 +379,7 @@
 
 /* flashrom.c */
 extern int verbose;
+extern const char *flashrom_version;
 #define printf_debug(x...) { if (verbose) printf(x); }
 void map_flash_registers(struct flashchip *flash);
 int read_memmapped(struct flashchip *flash, uint8_t *buf, int start, int len);