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

PXA3xx Development Platform (aka Zylonite)

configname: CONFIG_MACH_ZYLONITE

Linux Kernel Configuration
└─>Intel PXA2xx/PXA3xx Implementations
└─>PXA3xx Development Platform (aka Zylonite)
In linux kernel since version 2.6.24 (release Date: 2008-01-24)  

depends
CONFIG_ARCH_PXA |
NOT | CONFIG_ARCH_PXA_V7