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 67d34a6a391369269a2e5dba8a5f42cc4cd50231 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>