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

enable discard support

configname: CONFIG_STAGING_EXFAT_DISCARD

Linux Kernel Configuration
└─>Device Drivers
└─>Staging drivers
└─>enable discard support
In linux kernel since version 5.6 (release Date: 2020-03-29)