CONFIG_KGDB_DEFBAUD is not available for thedefaultarchitecture x86.
Result is shown for architecture sh
default or selected kernelversion does not have config value CONFIG_KGDB_DEFBAUD.
Result is shown for kernelversion 5.4.123

Baud rate

configname: CONFIG_KGDB_DEFBAUD

Linux Kernel Configuration
└─>Kernel hacking
└─>KGDB configuration options
└─>Baud rate
In linux kernel since version 2.6.12  
depends
CONFIG_KGDB