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

Basix, Connex, ws-200ax, ws-400ax systems

configname: CONFIG_MACH_GUMSTIX_F

Select target Gumstix board
└─>Basix, Connex, ws-200ax, ws-400ax systems
In linux kernel since version 2.6.26 (release Date: 2008-07-13)  
selects
CONFIG_PXA25x