CONFIG_SENSORS_RM3100 (not configurable)

modulename: rm3100-core.ko

configname: CONFIG_SENSORS_RM3100

Linux Kernel Configuration
└─>Device Drivers
└─>Industrial I/O support
└─>Magnetometer sensors
└─>SENSORS_RM3100
In linux kernel since version 5 (release Date: 2019-03-03)  
source code:
drivers/iio/magnetometer/rm3100-core.c

depends
CONFIG_IIO