CONFIG_MACH_SHEPHERD is not available for thedefaultarchitecture x86.
Result is shown for architecture arm

Enable Sharp SL-C750 (Shepherd) Support

configname: CONFIG_MACH_SHEPHERD

Linux Kernel Configuration
└─>Enable Sharp SL-C750 (Shepherd) Support
In linux kernel since version 2.6.20 (release Date: 2007-02-04)