spi: Migrate CONFIG_CF_SPI to Kconfig

Signed-off-by: Tuomas Tynkkynen <tuomas@tuxera.com>
diff --git a/configs/stmark2_defconfig b/configs/stmark2_defconfig
index 0bffde0..f7c6d92 100644
--- a/configs/stmark2_defconfig
+++ b/configs/stmark2_defconfig
@@ -23,4 +23,5 @@
 CONFIG_ENV_IS_IN_SPI_FLASH=y
 CONFIG_SPI_FLASH=y
 CONFIG_SPI_FLASH_MTD=y
+CONFIG_CF_SPI=y
 CONFIG_REGEX=y