Factor out register mapping code

Corresponding to flashrom svn r113 and coreboot v2 svn r2691.

Signed-off-by: Stefan Reinauer <stepan@coresystems.de>
Acked-by: Stefan Reinauer <stepan@coresystems.de>
diff --git a/flash.h b/flash.h
index ad9f61a..51ce38b 100644
--- a/flash.h
+++ b/flash.h
@@ -154,4 +154,6 @@
 
 extern int fd_mem;
 
+int map_flash_registers(struct flashchip *flash); /* flashrom.c */
+
 #endif				/* !__FLASH_H__ */