CONFIG_MACH_ZYLONITE is not available for the selected architecture x86.
Result is shown for architecture arm

PXA3xx Development Platform

configname: CONFIG_MACH_ZYLONITE

Select target board
└─>PXA3xx Development Platform
In linux kernel since version 2.6.24 (release Date: 2008-01-24)

depends
 or CONFIG_ARCH_PXA |
NOT | CONFIG_ARCH_PXA_V7