cfi_flash: convert to driver model

Convert cfi flash to driver model.

Signed-off-by: Thomas Chou <thomas@wytron.com.tw>
Reviewed-by: Simon Glass <sjg@chromium.org>
diff --git a/drivers/mtd/Kconfig b/drivers/mtd/Kconfig
index 23dff48..57e4b86 100644
--- a/drivers/mtd/Kconfig
+++ b/drivers/mtd/Kconfig
@@ -8,6 +8,17 @@
 	  flash, RAM and similar chips, often used for solid state file
 	  systems on embedded devices.
 
+config CFI_FLASH
+	bool "Enable Driver Model for CFI Flash driver"
+	depends on MTD
+	help
+	  The Common Flash Interface specification was developed by Intel,
+	  AMD and other flash manufactures. It provides a universal method
+	  for probing the capabilities of flash devices. If you wish to
+	  support any device that is CFI-compliant, you need to enable this
+	  option. Visit <http://www.amd.com/products/nvd/overview/cfi.html>
+	  for more information on CFI.
+
 endmenu
 
 source "drivers/mtd/nand/Kconfig"