CONFIG_S3C_DEV_HWMON is not available for thedefaultarchitecture x86.
Result is shown for architecture arm

CONFIG_S3C_DEV_HWMON (not configurable)

configname: CONFIG_S3C_DEV_HWMON

Linux Kernel Configuration
└─>S3C_DEV_HWMON
In linux kernel since version 2.6.35 (release Date: 2010-08-01)  
Compile in platform device definitions for HWMON

depends
CONFIG_PLAT_SAMSUNG |
| CONFIG_SAMSUNG_ATAGS

is depended by
CONFIG_MACH_SMARTQ