CONFIG_SUPERH64 is not available for thedefaultarchitecture x86.
Result is shown for architecture sh

CONFIG_SUPERH64 (not configurable)

configname: CONFIG_SUPERH64

Linux/SuperH Kernel Configuration
└─>SUPERH64
In linux kernel since version 2.6.12  
selects

CONFIG_HAVE_EXIT_THREAD
CONFIG_KALLSYMS