iwlwfifi: fix WANT_DEV_COREDUMP selection in Kconfig

Fix my mistake while sending Johannes's

commit aadede6e
Author: Johannes Berg <johannes.berg@intel.com>
Date:   Thu Oct 9 17:01:36 2014 +0200

    iwlwifi: mvm: port to devcoredump framework

Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>