cfi_flash: Export flash_sector_size() function.

Export flash_sector_size() function from drivers/mtd/cfi_flash.c,
so that it can be used in the upcoming cfi-mtd driver.

Signed-off-by: Piotr Ziecik <kosmo@semihalf.com>
Signed-off-by: Stefan Roese <sr@denx.de>
diff --git a/include/flash.h b/include/flash.h
index a6e91b5..8a00c2f 100644
--- a/include/flash.h
+++ b/include/flash.h
@@ -58,6 +58,8 @@
 #endif
 } flash_info_t;
 
+typedef unsigned long flash_sect_t;
+
 /*
  * Values for the width of the port
  */
@@ -92,6 +94,7 @@
 extern int flash_sect_erase (ulong addr_first, ulong addr_last);
 extern int flash_sect_protect (int flag, ulong addr_first, ulong addr_last);
 extern int flash_sect_roundb (ulong *addr);
+extern unsigned long flash_sector_size(flash_info_t *info, flash_sect_t sect);
 
 /* common/flash.c */
 extern void flash_protect (int flag, ulong from, ulong to, flash_info_t *info);