default or selected kernelversion does not have config value CONFIG_IIO_RING_BUFFER.
Result is shown for kernelversion 6.2.5

Enable buffer support within IIO

configname: CONFIG_IIO_RING_BUFFER

Linux Kernel Configuration
└─>Device Drivers
└─>Staging drivers
└─>Industrial I/O support
└─>Enable buffer support within IIO
In linux kernel since version 2.6.32 (release Date: 2009-12-02)  
Provide core support for various buffer based data
acquisition methods.