default or selected kernelversion does not have config value CONFIG_VEXPRESS_SYSCFG.
Result is shown for kernelversion 6.9.9

Versatile Express System Configuration driver

modulename: vexpress-syscfg.ko

configname: CONFIG_VEXPRESS_SYSCFG

Linux Kernel Configuration
└─>Device Drivers
└─>Misc devices
└─>Versatile Express System Configuration driver
In linux kernel since version 3.16 (release Date: 2014-08-03)  
ARM Ltd. Versatile Express uses specialised platform configuration
bus. System Configuration interface is one of the possible means
of generating transactions on this bus.

source code: