CONFIG_CPU_S5P6440 is not available for thedefaultarchitecture x86.
Result is shown for architecture arm
CONFIG_CPU_S5P6440 (not configurable)
modulename: cpu.ko
configname: CONFIG_CPU_S5P6440
Linux Kernel Configuration
└─>CPU_S5P6440
In linux kernel since version 2.6.34 (release Date: 2010-05-16)
Enable S5P6440 CPU support