CONFIG_CPU_SUBTYPE_SH7720 is not available for thedefaultarchitecture x86.
Result is shown for architecture sh
Support SH7720 processor
modulename: setup-sh7720.ko
configname: CONFIG_CPU_SUBTYPE_SH7720
Processor sub-type selection
└─>Support SH7720 processor
In linux kernel since version 2.6.24 (release Date: 2008-01-24)
Select SH7720 if you have a SH3-DSP SH7720 CPU.