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/voiceblue.h b/include/configs/voiceblue.h
index 8c827af..20917ee 100644
--- a/include/configs/voiceblue.h
+++ b/include/configs/voiceblue.h
@@ -60,7 +60,7 @@
  * FLASH organization
  */
 #define CFG_FLASH_CFI			/* Flash is CFI conformant */
-#define CFG_FLASH_CFI_DRIVER		/* Use the common driver */
+#define CONFIG_FLASH_CFI_DRIVER		/* Use the common driver */
 #define CFG_MAX_FLASH_BANKS	1
 #define CFG_FLASH_BASE		PHYS_FLASH_1