CONFIG_ARCH_VEXPRESS is not available for the selected architecture x86.
Result is shown for architecture arm64

ARM Ltd Platforms

modulename: v2m.ko

and/or

platsmp-vexpress.ko

configname: CONFIG_ARCH_VEXPRESS

Linux Kernel Configuration
└─>Platform selection
└─>ARM Ltd Platforms
In linux kernel since version 2.6.35 (release Date: 2010-08-01)
This enables support for the ARM Ltd Platforms.