mtd: kconfig: Fix CFI_FLASH dependency

The DM version CFI flash driver is in driver/mtd/cfi_flash.c, which
only gets built when FLASH_CFI_DRIVER is on. If CFI_FLASH is on but
FLASH_CFI_DRIVER is not, nothing is enabled at all.

Fix this dependency by selecting FLASH_CFI_DRIVER when CFI_FLASH is
enabled.
Signed-off-by: NBin Meng <bmeng.cn@gmail.com>
Reviewed-by: NStefan Roese <sr@denx.de>

drivers/mtd/Kconfig

@@ -42,6 +42,7 @@ config FLASH_CFI_DRIVER
 config CFI_FLASH
 	bool "Enable Driver Model for CFI Flash driver"
 	depends on DM_MTD
+	select FLASH_CFI_DRIVER
 	help
 	  The Common Flash Interface specification was developed by Intel,
 	  AMD and other flash manufactures. It provides a universal method