Convert CONFIG_BCH to Kconfig

This converts the following to Kconfig:
   CONFIG_BCH

Signed-off-by: Adam Ford <aford173@gmail.com>
Reviewed-by: Tom Rini <trini@konsulko.com>
diff --git a/configs/omap3_evm_defconfig b/configs/omap3_evm_defconfig
index d9e636a..9977e8e 100644
--- a/configs/omap3_evm_defconfig
+++ b/configs/omap3_evm_defconfig
@@ -57,6 +57,7 @@
 CONFIG_G_DNL_VENDOR_NUM=0x0451
 CONFIG_G_DNL_PRODUCT_NUM=0x5678
 CONFIG_FAT_WRITE=y
+CONFIG_BCH=y
 CONFIG_OF_LIBFDT=y
 CONFIG_OF_LIBFDT_OVERLAY=y
 CONFIG_SPL_OF_LIBFDT=y