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

PC PS/2 style Keyboard

configname: CONFIG_PC_KEYBOARD

Linux/PowerPC Kernel Configuration
└─>Kernel options
└─>PC PS/2 style Keyboard
In linux kernel since version 2.6.15 (release Date: 2006-01-02)  
depends
CONFIG_4xx or CONFIG_CPM2