CONFIG_S3C_DEV_HSMMC2 is not available for thedefaultarchitecture x86.
Result is shown for architecture arm

CONFIG_S3C_DEV_HSMMC2 (not configurable)

configname: CONFIG_S3C_DEV_HSMMC2

Linux Kernel Configuration
└─>Samsung Common options
└─>S3C_DEV_HSMMC2
In linux kernel since version 2.6.33 (release Date: 2010-02-24)  
Compile in platform device definitions for HSMMC channel 2