CONFIG_CPU_SUBTYPE_SH7300 is not available for thedefaultarchitecture x86.
Result is shown for architecture sh
default or selected kernelversion does not have config value CONFIG_CPU_SUBTYPE_SH7300.
Result is shown for kernelversion 5.4.123

SH7300

configname: CONFIG_CPU_SUBTYPE_SH7300

Processor subtype
└─>SH7300
In linux kernel since version 2.6.12  
depends
CONFIG_CPU_SH3