CONFIG_CPU_SUBTYPE_SH7706 is not available for thedefaultarchitecture x86.
Result is shown for architecture sh

Support SH7706 processor

modulename: setup-sh7709.ko

and/or

setup-sh770x.ko

configname: CONFIG_CPU_SUBTYPE_SH7706

Linux Kernel Configuration
└─>Processor selection
└─>Support SH7706 processor
In linux kernel since version 2.6.19 (release Date: 2006-11-29)  
Select SH7706 if you have a 133 Mhz SH-3 HD6417706 CPU.

source code:
arch/sh/kernel/cpu//sh3/setup-sh7709.c
selects
CONFIG_CPU_SH3

is selected by
CONFIG_SH_SHMIN

is depended by
CONFIG_SH_SHMIN