CONFIG_AT91_DEBUG_LL_DBGU2 is not available for thedefaultarchitecture x86.
Result is shown for architecture arm
default or selected kernelversion does not have config value CONFIG_AT91_DEBUG_LL_DBGU2.
Result is shown for kernelversion 5.4.229

Kernel low-level debugging on sama5d4

configname: CONFIG_AT91_DEBUG_LL_DBGU2

Kernel low-level debugging port
└─>Kernel low-level debugging on sama5d4
In linux kernel since version 3.18 (release Date: 2014-12-07)