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/kmcoge4_defconfig b/configs/kmcoge4_defconfig
index b8faced..2c0d7a0 100644
--- a/configs/kmcoge4_defconfig
+++ b/configs/kmcoge4_defconfig
@@ -39,4 +39,5 @@
 CONFIG_E1000=y
 CONFIG_SYS_NS16550=y
 CONFIG_FSL_ESPI=y
+CONFIG_BCH=y
 CONFIG_OF_LIBFDT=y