CONFIG_CPU_SUBTYPE_SH7712 is not available for thedefaultarchitecture x86.
Result is shown for architecture sh

Support SH7712 processor

modulename: setup-sh7710.ko

configname: CONFIG_CPU_SUBTYPE_SH7712

Processor sub-type selection
└─>Support SH7712 processor
In linux kernel since version 2.6.22 (release Date: 2007-07-08)  
Select SH7712 if you have a SH3-DSP SH7712 CPU.

source code: