CONFIG_CPU_SUBTYPE_SH7757 is not available for thedefaultarchitecture x86.
Result is shown for architecture sh

Support SH7757 processor

modulename: setup-sh7757.ko

configname: CONFIG_CPU_SUBTYPE_SH7757

Processor sub-type selection
└─>Support SH7757 processor
In linux kernel since version 2.6.32 (release Date: 2009-12-02)  
Select SH7757 if you have a SH4A SH7757 CPU.

source code: