CONFIG_ADMV8818 is not available for thedefaultarchitecture x86.
Result is shown for architecture 64BIT

Analog Devices ADMV8818 High-Pass and Low-Pass Filter

modulename: admv8818.ko

configname: CONFIG_ADMV8818

Linux Kernel Configuration
└─>Device Drivers
└─>Industrial I/O support
└─>Filters
└─>SPI support
└─>Common Clock Framework
└─>Analog Devices ADMV8818 High-Pass and Low-Pass Filter
In linux kernel since version 5.2 (release Date: 2019-07-07)  
Say yes here to build support for Analog Devices ADMV8818
2 GHz to 18 GHz, Digitally Tunable, High-Pass and Low-Pass Filter.

To compile this driver as a module, choose M here: the
modiule will be called admv8818.

source code: