It's desirable for allnconfig and tinyconfig targets to result in the
least amount of code possible. DISABLE_DEV_COREDUMP exists as a way to
switch off DEV_COREDUMP regardless if any drivers select
WANT_DEV_COREDUMP.
This patch renames the option to ENABLE_DEV_COREDUMP and setting it to
'n' (as in allnconfig or tinyconfig) will effectively disable device
coredump.