Convert CONFIG_CMD_BSP to Kconfig

This converts the following to Kconfig:
   CONFIG_CMD_BSP

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/configs/cm5200_defconfig b/configs/cm5200_defconfig
index 8b12a3a..5f691de 100644
--- a/configs/cm5200_defconfig
+++ b/configs/cm5200_defconfig
@@ -13,6 +13,7 @@
 CONFIG_CMD_MII=y
 CONFIG_CMD_PING=y
 CONFIG_CMD_SNTP=y
+CONFIG_CMD_BSP=y
 CONFIG_CMD_FAT=y
 CONFIG_MAC_PARTITION=y
 CONFIG_ISO_PARTITION=y