default or selected kernelversion does not have config value CONFIG_WESTBRIDGE.
Result is shown for kernelversion 5.6.18

West Bridge support

configname: CONFIG_WESTBRIDGE

Linux Kernel Configuration
└─>Device Drivers
└─>Staging drivers
└─>West Bridge support
In linux kernel since version 2.6.37 (release Date: 2011-01-04)  
This selects West Bridge Peripheral controller support.

If you want West Bridge support, you should say Y here.