CONFIG_RISCV_DMA_NONCOHERENT is not available for thedefaultarchitecture x86.
Result is shown for architecture riscv

CONFIG_RISCV_DMA_NONCOHERENT (not configurable)

modulename: dma-noncoherent.ko

configname: CONFIG_RISCV_DMA_NONCOHERENT

Linux Kernel Configuration
└─>RISCV_DMA_NONCOHERENT
In linux kernel since version 4.14.326 (release Date: 2023-09-23)  
source code:
arch/riscv/mm/dma-noncoherent.c