default or selected kernelversion does not have config value CONFIG_IWLCORE.
Result is shown for kernelversion 5.3.7

Intel Wireless Wifi Core

modulename: iwlcore.ko

configname: CONFIG_IWLCORE

Linux Kernel Configuration
└─>Device Drivers
└─>Network device support
└─>Wireless LAN
└─>Intel Wireless Wifi Core
In linux kernel since version 2.6.26 (release Date: 2008-07-13)  
source code:
drivers/net//wireless/iwlwifi/


is depended by
CONFIG_IWLAGN