default or selected kernelversion does not have config value CONFIG_BLK_DEV_NS87415.
Result is shown for kernelversion 6.9.9

NS87415 chipset support

modulename: ns87415.ko

configname: CONFIG_BLK_DEV_NS87415

Linux Kernel Configuration
└─>Device Drivers
└─>ATA/ATAPI/MFM/RLL support (DEPRECATED)
└─>NS87415 chipset support
In linux kernel since version 2.6.20 (release Date: 2007-02-04)  
This driver adds detection and support for the NS87415 chip
(used mainly on SPARC64 and PA-RISC machines).

Please read the comments at the top of <file:drivers/ide/ns87415.c>.

source code: