default or selected kernelversion does not have config value CONFIG_CROSS_COMPILE_COMPAT_VDSO.
Result is shown for kernelversion 5.4.123

32 bit Toolchain prefix for compat vDSO

configname: CONFIG_CROSS_COMPILE_COMPAT_VDSO

Linux Kernel Configuration
└─>Library routines
└─>32 bit Toolchain prefix for compat vDSO
In linux kernel since version 5.3 (release Date: 2019-09-15)  
Defines the cross-compiler prefix for compiling compat vDSO.
If a 64 bit compiler (i.e. x86_64) can compile the VDSO for
32 bit, it does not need to define this parameter.