CONFIG_CPU_SH4 is not available for thedefaultarchitecture x86.
Result is shown for architecture sh

CONFIG_CPU_SH4 (not configurable)

configname: CONFIG_CPU_SH4

Linux Kernel Configuration
└─>System type
└─>CPU_SH4
In linux kernel since version 2.6.12  

is selected by
CONFIG_SH_WDT