Convert CONFIG_BOARD_TYPES to Kconfig

This converts the following to Kconfig:
   CONFIG_BOARD_TYPES

Signed-off-by: Tom Rini <trini@konsulko.com>
diff --git a/configs/brsmarc1_defconfig b/configs/brsmarc1_defconfig
index a7cf98f..8333038 100644
--- a/configs/brsmarc1_defconfig
+++ b/configs/brsmarc1_defconfig
@@ -30,6 +30,7 @@
 CONFIG_VERSION_VARIABLE=y
 # CONFIG_DISPLAY_CPUINFO is not set
 # CONFIG_DISPLAY_BOARDINFO is not set
+CONFIG_BOARD_TYPES=y
 CONFIG_ARCH_MISC_INIT=y
 # CONFIG_SPL_RAW_IMAGE_SUPPORT is not set
 CONFIG_SPL_SYS_MALLOC_SIMPLE=y