CONFIG_ARCH_ZX is not available for thedefaultarchitecture x86.
Result is shown for architecture arm
default or selected kernelversion does not have config value CONFIG_ARCH_ZX.
Result is shown for kernelversion 6.9.9

ZTE ZX family

modulename: clk-zx296718.ko

configname: CONFIG_ARCH_ZX

Linux Kernel Configuration
└─>ZTE ZX family
In linux kernel since version 4.1 (release Date: 2015-06-21)  
Support for ZTE ZX-based family of processors. TV
set-top-box processor is supported. More will be
added soon.

source code:
drivers/clk/zte/clk-zx296718.c