Convert CONFIG_CMD_CHIP_CONFIG to Kconfig

This converts the following to Kconfig:
   CONFIG_CMD_CHIP_CONFIG

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/configs/io64_defconfig b/configs/io64_defconfig
index 3eb3ff6..9701135 100644
--- a/configs/io64_defconfig
+++ b/configs/io64_defconfig
@@ -2,6 +2,7 @@
 CONFIG_IDENT_STRING=" io64 0.02"
 CONFIG_4xx=y
 CONFIG_TARGET_IO64=y
+CONFIG_CMD_CHIP_CONFIG=y
 CONFIG_FIT=y
 CONFIG_FIT_VERBOSE=y
 CONFIG_OF_BOARD_SETUP=y