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

CONFIG_SH_ALPHA_BOARD (not configurable)

configname: CONFIG_SH_ALPHA_BOARD

Linux Kernel Configuration
└─>Board support
└─>SH_ALPHA_BOARD
In linux kernel since version 2.6.38 (release Date: 2011-03-14)