default or selected kernelversion does not have config value CONFIG_IIO_BFIN_TMR_TRIGGER.
Result is shown for kernelversion 6.7-rc3

Blackfin TIMER trigger

modulename: iio-trig-bfin-timer.ko

configname: CONFIG_IIO_BFIN_TMR_TRIGGER

Linux Kernel Configuration
└─>Device Drivers
└─>Staging drivers
└─>IIO staging drivers
└─>Blackfin TIMER trigger
In linux kernel since version 2.6.39 (release Date: 2011-05-18)  
Provides support for using a Blackfin timer as IIO triggers.
If unsure, say N (but it's safe to say "Y").

To compile this driver as a module, choose M here: the
module will be called iio-trig-bfin-timer.

source code: