kconfig: replace 'oldnoconfig' with 'olddefconfig', and keep the old name as an alias

kconfig: replace 'oldnoconfig' with 'olddefconfig', and keep the old name as an alias

As 6bafe3e214a9387feabab0330e7b8024b858412c said, 'oldnoconfig' doesn't
set new symbols to 'n', but instead sets it to their default values.

So, this patch replaces 'oldnoconfig' with 'olddefconfig', stop making
people confused, and keep the old name 'oldnoconfig' as an alias,
because people already are dependent on its behavior with the
counter-intuitive name.

Signed-off-by: Adam Lee <adam8157@gmail.com>
Signed-off-by: Michal Marek <mmarek@suse.cz>