CONFIG_NR_DMA_CHANNELS is not available for the default architecture x86.
Result is shown for architecture sh
default or selected kernelversion does not have config value CONFIG_NR_DMA_CHANNELS.
Result is shown for kernelversion 6.2.5

Maximum number of DMA channels


Linux Kernel Configuration
└─> DMA support
└─> Maximum number of DMA channels

In linux kernel since version 2.6.12  

This allows you to specify the maximum number of DMA channels to
support. Setting this to a higher value allows for cascading DMACs
with additional channels.