default or selected kernelversion does not have config value CONFIG_STAGING_EXFAT_FS.
Result is shown for kernelversion 5.8-rc2

exFAT fs support

modulename: exfat.ko

configname: CONFIG_STAGING_EXFAT_FS

Linux Kernel Configuration
└─>Device Drivers
└─>Staging drivers
└─>exFAT fs support
In linux kernel since version 5.6 (release Date: 2020-03-29)  
This adds support for the exFAT file system.

source code:
drivers/staging/exfat/
selects
CONFIG_NLS