CONFIG_CPU_SUBTYPE_SH7724 is not available for thedefaultarchitecture x86.
Result is shown for architecture sh

Support SH7724 processor

modulename: setup-sh7724.ko

configname: CONFIG_CPU_SUBTYPE_SH7724

Processor sub-type selection
└─>Support SH7724 processor
In linux kernel since version 2.6.31 (release Date: 2009-09-09)  
Select SH7724 if you have an SH-MobileR2R CPU.

source code: