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/v38b.h b/include/configs/v38b.h
index c203522..3574548 100644
--- a/include/configs/v38b.h
+++ b/include/configs/v38b.h
@@ -201,7 +201,7 @@
  * Flash configuration - use CFI driver
  */
 #define CFG_FLASH_CFI		1		/* Flash is CFI conformant */
-#define CFG_FLASH_CFI_DRIVER	1		/* Use the common driver */
+#define CONFIG_FLASH_CFI_DRIVER	1		/* Use the common driver */
 #define CFG_FLASH_CFI_AMD_RESET	1
 #define CFG_FLASH_BASE		0xFF000000
 #define CFG_MAX_FLASH_BANKS	1		/* max num of flash banks */