It does not seem worth having an option to enable another sub-command in
this legacy driver. Drop this option so that the sub-command is always
available.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Philipp Tomsich <philipp.tomsich@theobroma-systems.com>