CONFIG_SND_HDA_EXT_CORE (not configurable)

modulename: snd-hda-ext-core.ko

configname: CONFIG_SND_HDA_EXT_CORE

Linux Kernel Configuration
└─>Device Drivers
└─>Sound card support
└─>Advanced Linux Sound Architecture
└─>SND_HDA_EXT_CORE
In linux kernel since version 3.10 (release Date: 2013-06-30)  
source code:
sound/hda//ext/