CONFIG_INTEL_IDXD is not available for thedefaultarchitecture x86.
Result is shown for architecture 64BIT

Intel Data Accelerators support

modulename: idxd.ko

configname: CONFIG_INTEL_IDXD

Linux Kernel Configuration
└─>Device Drivers
└─>DMA Engine support
└─>PCI support
└─>Intel Data Accelerators support
In linux kernel since version 5.1 (release Date: 2019-05-05)  
Enable support for the Intel(R) data accelerators present
in Intel Xeon CPU.

Say Y if you have such a platform.

If unsure, say N.

source code: