drivers/mtd: Move conditional compilation to Makefile

rename CFG_FLASH_CFI_DRIVER to CONFIG_FLASH_CFI_DRIVER

Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
diff --git a/include/configs/zeus.h b/include/configs/zeus.h
index cd120df..b50cba5 100644
--- a/include/configs/zeus.h
+++ b/include/configs/zeus.h
@@ -210,7 +210,7 @@
  * FLASH organization
  */
 #define CFG_FLASH_CFI				/* The flash is CFI compatible	*/
-#define CFG_FLASH_CFI_DRIVER			/* Use common CFI driver	*/
+#define CONFIG_FLASH_CFI_DRIVER			/* Use common CFI driver	*/
 
 #define CFG_FLASH_BANKS_LIST	{ CFG_FLASH_BASE }