CONFIG_CPU_SUBTYPE_SH7709 is not available for thedefaultarchitecture x86.
Result is shown for architecture sh

Support SH7709 processor

modulename: setup-sh770x.ko

configname: CONFIG_CPU_SUBTYPE_SH7709

Processor sub-type selection
└─>Support SH7709 processor
In linux kernel since version 2.6.12  
Select SH7709 if you have a 80 Mhz SH-3 HD6417709 CPU.

source code:
arch/sh/kernel/cpu/sh3/setup-sh770x.c
selects
CONFIG_CPU_SH3

is selected by
CONFIG_SH_POLARIS