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/apf27_defconfig b/configs/apf27_defconfig
index 071ff7f..e22dc07 100644
--- a/configs/apf27_defconfig
+++ b/configs/apf27_defconfig
@@ -18,6 +18,7 @@
 CONFIG_CMD_MII=y
 CONFIG_CMD_PING=y
 CONFIG_CMD_DNS=y
+CONFIG_CMD_BSP=y
 CONFIG_CMD_CACHE=y
 CONFIG_CMD_EXT2=y
 CONFIG_CMD_FAT=y