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

CONFIG_ARCH_MTD_XIP (not configurable)

configname: CONFIG_ARCH_MTD_XIP

Linux Kernel Configuration
└─>ARCH_MTD_XIP
In linux kernel since version 2.6.16 (release Date: 2006-03-19)  
is depended by
CONFIG_ARCH_PXA