sandbox: Cleanup order and extra defines in defconfig

The defconfigs should not be edited directly. They should be generated
by editing the .config (through menuconfig or whatever) and then run
make savedefconfig to have the Kconfig system generate a clean defconfig

I did this for sandbox here with no actual changes.

Signed-off-by: Joe Hershberger <joe.hershberger@ni.com>
Reviewed-by: Simon Glass <sjg@chromium.org>