moveconfig: Always run savedefconfig on the moved config

This will ensure that the order of the defconfig entries will always
match that of the Kconfig files. After one slightly painful (but
still early in the process) pass over all boards, this should keep
the defconfigs clean from here on.

Users must edit the Kconfig first to add the menu entries and then run
moveconfig.py to update the defconfig files and the include configs.

As such, moveconfig.py cannot compare against the '.config' contents.

Signed-off-by: Joe Hershberger <joe.hershberger@ni.com>
Acked-by: Masahiro Yamada <yamada.masahiro@socionext.com>