CONFIG_DMA_MAYBE_COHERENT is not available for thedefaultarchitecture x86.
Result is shown for architecture mips

CONFIG_DMA_MAYBE_COHERENT (not configurable)

configname: CONFIG_DMA_MAYBE_COHERENT

Linux Kernel Configuration
└─>DMA_MAYBE_COHERENT
In linux kernel since version 3.14 (release Date: 2014-03-30)