CONFIG_MACH_SMDK6410 is not available for thedefaultarchitecture x86.
Result is shown for architecture arm

SMDK6410

configname: CONFIG_MACH_SMDK6410

Linux Kernel Configuration
└─>Samsung S3C64XX
└─>SMDK6410
In linux kernel since version 2.6.29 (release Date: 2009-03-23)  
Machine support for the Samsung SMDK6410