CONFIG_CPU_SUBTYPE_SH7604 is not available for thedefaultarchitecture x86.
Result is shown for architecture sh

SH7604

configname: CONFIG_CPU_SUBTYPE_SH7604

Processor subtype
└─>SH7604
In linux kernel since version 2.6.12  
Select SH7604 if you have SH7604

selects

CONFIG_CPU_SH2

depends
CONFIG_CPU_SH2