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

CONFIG_ARM_DMA_USE_IOMMU (not configurable)

configname: CONFIG_ARM_DMA_USE_IOMMU

Linux Kernel Configuration
└─>ARM_DMA_USE_IOMMU
In linux kernel since version 3.1 (release Date: 2011-10-24)